diff --git a/caca/caca.h b/caca/caca.h
index c85d29f..0a2283e 100644
--- a/caca/caca.h
+++ b/caca/caca.h
@@ -192,9 +192,9 @@ __extern caca_display_t * caca_create_display(cucul_canvas_t *);
 __extern int caca_free_display(caca_display_t *);
 __extern int caca_refresh_display(caca_display_t *);
 __extern int caca_set_display_time(caca_display_t *, unsigned int);
-__extern unsigned int caca_get_display_time(caca_display_t *);
-__extern unsigned int caca_get_display_width(caca_display_t *);
-__extern unsigned int caca_get_display_height(caca_display_t *);
+__extern unsigned int caca_get_display_time(caca_display_t const *);
+__extern unsigned int caca_get_display_width(caca_display_t const *);
+__extern unsigned int caca_get_display_height(caca_display_t const *);
 __extern int caca_set_display_title(caca_display_t *, char const *);
 /*  @} */
 
@@ -206,8 +206,8 @@ __extern int caca_set_display_title(caca_display_t *, char const *);
  *  @{ */
 __extern int caca_get_event(caca_display_t *, unsigned int,
                             caca_event_t *, int);
-__extern unsigned int caca_get_mouse_x(caca_display_t *);
-__extern unsigned int caca_get_mouse_y(caca_display_t *);
+__extern unsigned int caca_get_mouse_x(caca_display_t const *);
+__extern unsigned int caca_get_mouse_y(caca_display_t const *);
 __extern int caca_set_mouse(caca_display_t *, int);
 __extern int caca_set_cursor(caca_display_t *, int);
 /*  @} */
diff --git a/caca/caca_internals.h b/caca/caca_internals.h
index d98cced..7fb9181 100644
--- a/caca/caca_internals.h
+++ b/caca/caca_internals.h
@@ -108,8 +108,8 @@ struct caca_display
         int (* init_graphics) (caca_display_t *);
         int (* end_graphics) (caca_display_t *);
         int (* set_display_title) (caca_display_t *, char const *);
-        unsigned int (* get_display_width) (caca_display_t *);
-        unsigned int (* get_display_height) (caca_display_t *);
+        unsigned int (* get_display_width) (caca_display_t const *);
+        unsigned int (* get_display_height) (caca_display_t const *);
         void (* display) (caca_display_t *);
         void (* handle_resize) (caca_display_t *);
         int (* get_event) (caca_display_t *, caca_event_t *);
diff --git a/caca/driver_conio.c b/caca/driver_conio.c
index 56cc58f..89ea647 100644
--- a/caca/driver_conio.c
+++ b/caca/driver_conio.c
@@ -83,13 +83,13 @@ static int conio_set_display_title(caca_display_t *dp, char const *title)
     return -1;
 }
 
-static unsigned int conio_get_display_width(caca_display_t *dp)
+static unsigned int conio_get_display_width(caca_display_t const *dp)
 {
     /* Fallback to a 6x10 font */
     return dp->cv->width * 6;
 }
 
-static unsigned int conio_get_display_height(caca_display_t *dp)
+static unsigned int conio_get_display_height(caca_display_t const *dp)
 {
     /* Fallback to a 6x10 font */
     return dp->cv->height * 10;
diff --git a/caca/driver_gl.c b/caca/driver_gl.c
index 905159f..9a5206b 100644
--- a/caca/driver_gl.c
+++ b/caca/driver_gl.c
@@ -197,12 +197,12 @@ static int gl_set_display_title(caca_display_t *dp, char const *title)
     return 0;
 }
 
-static unsigned int gl_get_display_width(caca_display_t *dp)
+static unsigned int gl_get_display_width(caca_display_t const *dp)
 {
     return dp->drv.p->width;
 }
 
-static unsigned int gl_get_display_height(caca_display_t *dp)
+static unsigned int gl_get_display_height(caca_display_t const *dp)
 {
     return dp->drv.p->height;
 }
diff --git a/caca/driver_ncurses.c b/caca/driver_ncurses.c
index c0c1040..fa498ef 100644
--- a/caca/driver_ncurses.c
+++ b/caca/driver_ncurses.c
@@ -326,13 +326,13 @@ static int ncurses_set_display_title(caca_display_t *dp, char const *title)
     return 0;
 }
 
-static unsigned int ncurses_get_display_width(caca_display_t *dp)
+static unsigned int ncurses_get_display_width(caca_display_t const *dp)
 {
     /* Fallback to a 6x10 font */
     return dp->cv->width * 6;
 }
 
-static unsigned int ncurses_get_display_height(caca_display_t *dp)
+static unsigned int ncurses_get_display_height(caca_display_t const *dp)
 {
     /* Fallback to a 6x10 font */
     return dp->cv->height * 10;
diff --git a/caca/driver_raw.c b/caca/driver_raw.c
index cfa6ca5..16784e8 100644
--- a/caca/driver_raw.c
+++ b/caca/driver_raw.c
@@ -55,12 +55,12 @@ static int raw_set_display_title(caca_display_t *dp, char const *title)
     return -1;
 }
 
-static unsigned int raw_get_display_width(caca_display_t *dp)
+static unsigned int raw_get_display_width(caca_display_t const *dp)
 {
     return 0;
 }
 
-static unsigned int raw_get_display_height(caca_display_t *dp)
+static unsigned int raw_get_display_height(caca_display_t const *dp)
 {
     return 0;
 }
diff --git a/caca/driver_slang.c b/caca/driver_slang.c
index 31d64b4..4c42a11 100644
--- a/caca/driver_slang.c
+++ b/caca/driver_slang.c
@@ -193,13 +193,13 @@ static int slang_set_display_title(caca_display_t *dp, char const *title)
     return 0;
 }
 
-static unsigned int slang_get_display_width(caca_display_t *dp)
+static unsigned int slang_get_display_width(caca_display_t const *dp)
 {
     /* Fallback to a 6x10 font */
     return dp->cv->width * 6;
 }
 
-static unsigned int slang_get_display_height(caca_display_t *dp)
+static unsigned int slang_get_display_height(caca_display_t const *dp)
 {
     /* Fallback to a 6x10 font */
     return dp->cv->height * 10;
diff --git a/caca/driver_vga.c b/caca/driver_vga.c
index a594c0f..4c037c2 100644
--- a/caca/driver_vga.c
+++ b/caca/driver_vga.c
@@ -101,13 +101,13 @@ static int vga_set_display_title(caca_display_t *dp, char const *title)
     return -1;
 }
 
-static unsigned int vga_get_display_width(caca_display_t *dp)
+static unsigned int vga_get_display_width(caca_display_t const *dp)
 {
     /* Fallback to a 320x200 screen */
     return 320;
 }
 
-static unsigned int vga_get_display_height(caca_display_t *dp)
+static unsigned int vga_get_display_height(caca_display_t const *dp)
 {
     /* Fallback to a 320x200 screen */
     return 200;
diff --git a/caca/driver_win32.c b/caca/driver_win32.c
index 0026cc1..71f0c2d 100644
--- a/caca/driver_win32.c
+++ b/caca/driver_win32.c
@@ -171,7 +171,7 @@ static int win32_set_display_title(caca_display_t *dp, char const *title)
     return 0;
 }
 
-static unsigned int win32_get_display_width(caca_display_t *dp)
+static unsigned int win32_get_display_width(caca_display_t const *dp)
 {
     /* FIXME */
 
@@ -179,7 +179,7 @@ static unsigned int win32_get_display_width(caca_display_t *dp)
     return dp->cv->width * 6;
 }
 
-static unsigned int win32_get_display_height(caca_display_t *dp)
+static unsigned int win32_get_display_height(caca_display_t const *dp)
 {
     /* FIXME */
 
diff --git a/caca/driver_x11.c b/caca/driver_x11.c
index 08d262e..4fd29fa 100644
--- a/caca/driver_x11.c
+++ b/caca/driver_x11.c
@@ -274,12 +274,12 @@ static int x11_set_display_title(caca_display_t *dp, char const *title)
     return 0;
 }
 
-static unsigned int x11_get_display_width(caca_display_t *dp)
+static unsigned int x11_get_display_width(caca_display_t const *dp)
 {
     return dp->cv->width * dp->drv.p->font_width;
 }
 
-static unsigned int x11_get_display_height(caca_display_t *dp)
+static unsigned int x11_get_display_height(caca_display_t const *dp)
 {
     return dp->cv->height * dp->drv.p->font_height;
 }
diff --git a/caca/event.c b/caca/event.c
index 237685d..71c0a93 100644
--- a/caca/event.c
+++ b/caca/event.c
@@ -125,10 +125,10 @@ int caca_get_event(caca_display_t *dp, unsigned int event_mask,
  *  \param dp The libcaca graphical context.
  *  \return The X mouse coordinate.
  */
-unsigned int caca_get_mouse_x(caca_display_t *dp)
+unsigned int caca_get_mouse_x(caca_display_t const *dp)
 {
     if(dp->mouse.x >= dp->cv->width)
-        dp->mouse.x = dp->cv->width - 1;
+        return dp->cv->width - 1;
 
     return dp->mouse.x;
 }
@@ -145,10 +145,10 @@ unsigned int caca_get_mouse_x(caca_display_t *dp)
  *  \param dp The libcaca graphical context.
  *  \return The Y mouse coordinate.
  */
-unsigned int caca_get_mouse_y(caca_display_t *dp)
+unsigned int caca_get_mouse_y(caca_display_t const *dp)
 {
     if(dp->mouse.y >= dp->cv->height)
-        dp->mouse.y = dp->cv->height - 1;
+        return dp->cv->height - 1;
 
     return dp->mouse.y;
 }
diff --git a/caca/graphics.c b/caca/graphics.c
index afc6542..8c09d6d 100644
--- a/caca/graphics.c
+++ b/caca/graphics.c
@@ -64,7 +64,7 @@ int caca_set_display_title(caca_display_t *dp, char const *title)
  *  \param dp The libcaca display context.
  *  \return The display width.
  */
-unsigned int caca_get_display_width(caca_display_t *dp)
+unsigned int caca_get_display_width(caca_display_t const *dp)
 {
     return dp->drv.get_display_width(dp);
 }
@@ -81,7 +81,7 @@ unsigned int caca_get_display_width(caca_display_t *dp)
  *  \param dp The libcaca display context.
  *  \return The display height.
  */
-unsigned int caca_get_display_height(caca_display_t *dp)
+unsigned int caca_get_display_height(caca_display_t const *dp)
 {
     return dp->drv.get_display_height(dp);
 }
@@ -120,7 +120,7 @@ int caca_set_display_time(caca_display_t *dp, unsigned int usec)
  *  \param dp The libcaca display context.
  *  \return The render time in microseconds.
  */
-unsigned int caca_get_display_time(caca_display_t *dp)
+unsigned int caca_get_display_time(caca_display_t const *dp)
 {
     return dp->rendertime;
 }
diff --git a/cucul/attr.c b/cucul/attr.c
index 797c1c3..5464014 100644
--- a/cucul/attr.c
+++ b/cucul/attr.c
@@ -50,7 +50,7 @@ static uint8_t nearest_ansi(uint16_t);
  *  \param y Y coordinate.
  *  \return The requested attribute.
  */
-unsigned long int cucul_get_attr(cucul_canvas_t *cv, int x, int y)
+unsigned long int cucul_get_attr(cucul_canvas_t const *cv, int x, int y)
 {
     if(x < 0 || x >= (int)cv->width || y < 0 || y >= (int)cv->height)
         return (unsigned long int)cv->curattr;
diff --git a/cucul/canvas.c b/cucul/canvas.c
index d75b348..e5b4ff7 100644
--- a/cucul/canvas.c
+++ b/cucul/canvas.c
@@ -69,7 +69,7 @@ int cucul_gotoxy(cucul_canvas_t *cv, int x, int y)
  *  \param cv A handle to the libcucul canvas.
  *  \return The cursor's X coordinate.
  */
-int cucul_get_cursor_x(cucul_canvas_t *cv)
+int cucul_get_cursor_x(cucul_canvas_t const *cv)
 {
     return cv->frames[cv->frame].x;
 }
@@ -83,7 +83,7 @@ int cucul_get_cursor_x(cucul_canvas_t *cv)
  *  \param cv A handle to the libcucul canvas.
  *  \return The cursor's Y coordinate.
  */
-int cucul_get_cursor_y(cucul_canvas_t *cv)
+int cucul_get_cursor_y(cucul_canvas_t const *cv)
 {
     return cv->frames[cv->frame].y;
 }
@@ -192,7 +192,7 @@ int cucul_put_char(cucul_canvas_t *cv, int x, int y, unsigned long int ch)
  *  \param y Y coordinate.
  *  \return This function always returns 0.
  */
-unsigned long int cucul_get_char(cucul_canvas_t *cv, int x, int y)
+unsigned long int cucul_get_char(cucul_canvas_t const *cv, int x, int y)
 {
     if(x < 0 || x >= (int)cv->width || y < 0 || y >= (int)cv->height)
         return ' ';
@@ -340,7 +340,7 @@ int cucul_set_canvas_handle(cucul_canvas_t *cv, int x, int y)
  *  \param cv A handle to the libcucul canvas.
  *  \return The canvas' handle's X coordinate.
  */
-int cucul_get_canvas_handle_x(cucul_canvas_t *cv)
+int cucul_get_canvas_handle_x(cucul_canvas_t const *cv)
 {
     return cv->frames[cv->frame].handlex;
 }
@@ -354,7 +354,7 @@ int cucul_get_canvas_handle_x(cucul_canvas_t *cv)
  *  \param cv A handle to the libcucul canvas.
  *  \return The canvas' handle's Y coordinate.
  */
-int cucul_get_canvas_handle_y(cucul_canvas_t *cv)
+int cucul_get_canvas_handle_y(cucul_canvas_t const *cv)
 {
     return cv->frames[cv->frame].handley;
 }
diff --git a/cucul/cucul.c b/cucul/cucul.c
index 80483bd..0527f00 100644
--- a/cucul/cucul.c
+++ b/cucul/cucul.c
@@ -149,7 +149,7 @@ int cucul_set_canvas_size(cucul_canvas_t *cv, unsigned int width,
  *  \param cv A libcucul canvas
  *  \return The canvas width.
  */
-unsigned int cucul_get_canvas_width(cucul_canvas_t *cv)
+unsigned int cucul_get_canvas_width(cucul_canvas_t const *cv)
 {
     return cv->width;
 }
@@ -163,7 +163,7 @@ unsigned int cucul_get_canvas_width(cucul_canvas_t *cv)
  *  \param cv A libcucul canvas
  *  \return The canvas height.
  */
-unsigned int cucul_get_canvas_height(cucul_canvas_t *cv)
+unsigned int cucul_get_canvas_height(cucul_canvas_t const *cv)
 {
     return cv->height;
 }
diff --git a/cucul/cucul.h b/cucul/cucul.h
index 3d1e401..bd2e5f5 100644
--- a/cucul/cucul.h
+++ b/cucul/cucul.h
@@ -86,8 +86,8 @@ typedef struct cucul_font cucul_font_t;
 __extern cucul_canvas_t * cucul_create_canvas(unsigned int, unsigned int);
 __extern int cucul_set_canvas_size(cucul_canvas_t *, unsigned int,
                                    unsigned int);
-__extern unsigned int cucul_get_canvas_width(cucul_canvas_t *);
-__extern unsigned int cucul_get_canvas_height(cucul_canvas_t *);
+__extern unsigned int cucul_get_canvas_width(cucul_canvas_t const *);
+__extern unsigned int cucul_get_canvas_height(cucul_canvas_t const *);
 __extern int cucul_free_canvas(cucul_canvas_t *);
 __extern int cucul_rand(int, int);
 /*  @} */
@@ -100,12 +100,12 @@ __extern int cucul_rand(int, int);
  *  @{ */
 #define CUCUL_MAGIC_FULLWIDTH 0x000ffffe /**< Used to indicate that the previous character was a fullwidth glyph. */
 __extern int cucul_gotoxy(cucul_canvas_t *, int, int);
-__extern int cucul_get_cursor_x(cucul_canvas_t *);
-__extern int cucul_get_cursor_y(cucul_canvas_t *);
+__extern int cucul_get_cursor_x(cucul_canvas_t const *);
+__extern int cucul_get_cursor_y(cucul_canvas_t const *);
 __extern int cucul_put_char(cucul_canvas_t *, int, int, unsigned long int);
-__extern unsigned long int cucul_get_char(cucul_canvas_t *, int, int);
+__extern unsigned long int cucul_get_char(cucul_canvas_t const *, int, int);
 __extern int cucul_put_str(cucul_canvas_t *, int, int, char const *);
-__extern unsigned long int cucul_get_attr(cucul_canvas_t *, int, int);
+__extern unsigned long int cucul_get_attr(cucul_canvas_t const *, int, int);
 __extern int cucul_set_attr(cucul_canvas_t *, unsigned long int);
 __extern int cucul_put_attr(cucul_canvas_t *, int, int, unsigned long int);
 __extern int cucul_set_color_ansi(cucul_canvas_t *, unsigned char,
@@ -115,8 +115,8 @@ __extern int cucul_set_color_argb(cucul_canvas_t *, unsigned int,
 __extern int cucul_printf(cucul_canvas_t *, int, int, char const *, ...);
 __extern int cucul_clear_canvas(cucul_canvas_t *);
 __extern int cucul_set_canvas_handle(cucul_canvas_t *, int, int);
-__extern int cucul_get_canvas_handle_x(cucul_canvas_t *);
-__extern int cucul_get_canvas_handle_y(cucul_canvas_t *);
+__extern int cucul_get_canvas_handle_x(cucul_canvas_t const *);
+__extern int cucul_get_canvas_handle_y(cucul_canvas_t const *);
 __extern int cucul_blit(cucul_canvas_t *, int, int, cucul_canvas_t const *,
                         cucul_canvas_t const *);
 __extern int cucul_set_canvas_boundaries(cucul_canvas_t *, int, int,
@@ -204,9 +204,9 @@ __extern int cucul_fill_triangle(cucul_canvas_t *, int, int, int, int, int,
  *  removal, copying etc.
  *
  *  @{ */
-__extern unsigned int cucul_get_frame_count(cucul_canvas_t *);
+__extern unsigned int cucul_get_frame_count(cucul_canvas_t const *);
 __extern int cucul_set_frame(cucul_canvas_t *, unsigned int);
-__extern char const *cucul_get_frame_name(cucul_canvas_t *);
+__extern char const *cucul_get_frame_name(cucul_canvas_t const *);
 __extern int cucul_set_frame_name(cucul_canvas_t *, char const *);
 __extern int cucul_create_frame(cucul_canvas_t *, unsigned int);
 __extern int cucul_free_frame(cucul_canvas_t *, unsigned int);
@@ -228,11 +228,11 @@ __extern int cucul_set_dither_palette(cucul_dither_t *,
                                       unsigned int r[], unsigned int g[],
                                       unsigned int b[], unsigned int a[]);
 __extern int cucul_set_dither_brightness(cucul_dither_t *, float);
-__extern float cucul_get_dither_brightness(cucul_dither_t *);
+__extern float cucul_get_dither_brightness(cucul_dither_t const *);
 __extern int cucul_set_dither_gamma(cucul_dither_t *, float);
-__extern float cucul_get_dither_gamma(cucul_dither_t *);
+__extern float cucul_get_dither_gamma(cucul_dither_t const *);
 __extern int cucul_set_dither_contrast(cucul_dither_t *, float);
-__extern float cucul_get_dither_contrast(cucul_dither_t *);
+__extern float cucul_get_dither_contrast(cucul_dither_t const *);
 __extern int cucul_set_dither_antialias(cucul_dither_t *, char const *);
 __extern char const * const * cucul_get_dither_antialias_list(cucul_dither_t
                                                               const *);
@@ -262,11 +262,12 @@ __extern int cucul_free_dither(cucul_dither_t *);
  *  @{ */
 __extern cucul_font_t *cucul_load_font(void const *, unsigned int);
 __extern char const * const * cucul_get_font_list(void);
-__extern unsigned int cucul_get_font_width(cucul_font_t *);
-__extern unsigned int cucul_get_font_height(cucul_font_t *);
-__extern unsigned long int const *cucul_get_font_blocks(cucul_font_t *);
-__extern int cucul_render_canvas(cucul_canvas_t *, cucul_font_t *, void *,
-                                 unsigned int, unsigned int, unsigned int);
+__extern unsigned int cucul_get_font_width(cucul_font_t const *);
+__extern unsigned int cucul_get_font_height(cucul_font_t const *);
+__extern unsigned long int const *cucul_get_font_blocks(cucul_font_t const *);
+__extern int cucul_render_canvas(cucul_canvas_t const *, cucul_font_t const *,
+                                 void *, unsigned int, unsigned int,
+                                 unsigned int);
 __extern int cucul_free_font(cucul_font_t *);
 /*  @} */
 
@@ -282,7 +283,7 @@ __extern long int cucul_import_memory(cucul_canvas_t *, void const *,
 __extern long int cucul_import_file(cucul_canvas_t *, char const *,
                                     char const *);
 __extern char const * const * cucul_get_import_list(void);
-__extern void *cucul_export_memory(cucul_canvas_t *, char const *,
+__extern void *cucul_export_memory(cucul_canvas_t const *, char const *,
                                    unsigned long int *);
 __extern char const * const * cucul_get_export_list(void);
 /*  @} */
diff --git a/cucul/dither.c b/cucul/dither.c
index f0a26e8..1e47888 100644
--- a/cucul/dither.c
+++ b/cucul/dither.c
@@ -441,7 +441,7 @@ int cucul_set_dither_brightness(cucul_dither_t *d, float brightness)
  *  \param d Dither object.
  *  \return Brightness value.
  */
-float cucul_get_dither_brightness(cucul_dither_t *d)
+float cucul_get_dither_brightness(cucul_dither_t const *d)
 {
     return d->brightness;
 }
@@ -493,7 +493,7 @@ int cucul_set_dither_gamma(cucul_dither_t *d, float gamma)
  *  \param d Dither object.
  *  \return Gamma value.
  */
-float cucul_get_dither_gamma(cucul_dither_t *d)
+float cucul_get_dither_gamma(cucul_dither_t const *d)
 {
     return d->gamma;
 }
@@ -526,7 +526,7 @@ int cucul_set_dither_contrast(cucul_dither_t *d, float contrast)
  *  \param d Dither object.
  *  \return Contrast value.
  */
-float cucul_get_dither_contrast(cucul_dither_t *d)
+float cucul_get_dither_contrast(cucul_dither_t const *d)
 {
     return d->contrast;
 }
diff --git a/cucul/export.c b/cucul/export.c
index 00cdf36..ab73396 100644
--- a/cucul/export.c
+++ b/cucul/export.c
@@ -45,15 +45,15 @@ static inline int sprintu16(char *s, uint16_t x)
     return 2;
 }
 
-static void *export_caca(cucul_canvas_t *, unsigned long int *);
-static void *export_ansi(cucul_canvas_t *, unsigned long int *);
-static void *export_utf8(cucul_canvas_t *, unsigned long int *, int);
-static void *export_html(cucul_canvas_t *, unsigned long int *);
-static void *export_html3(cucul_canvas_t *, unsigned long int *);
-static void *export_irc(cucul_canvas_t *, unsigned long int *);
-static void *export_ps(cucul_canvas_t *, unsigned long int *);
-static void *export_svg(cucul_canvas_t *, unsigned long int *);
-static void *export_tga(cucul_canvas_t *, unsigned long int *);
+static void *export_caca(cucul_canvas_t const *, unsigned long int *);
+static void *export_ansi(cucul_canvas_t const *, unsigned long int *);
+static void *export_utf8(cucul_canvas_t const *, unsigned long int *, int);
+static void *export_html(cucul_canvas_t const *, unsigned long int *);
+static void *export_html3(cucul_canvas_t const *, unsigned long int *);
+static void *export_irc(cucul_canvas_t const *, unsigned long int *);
+static void *export_ps(cucul_canvas_t const *, unsigned long int *);
+static void *export_svg(cucul_canvas_t const *, unsigned long int *);
+static void *export_tga(cucul_canvas_t const *, unsigned long int *);
 
 /** \brief Export a canvas into a foreign format.
  *
@@ -82,7 +82,7 @@ static void *export_tga(cucul_canvas_t *, unsigned long int *);
  *         allocated bytes will be written.
  *  \return A pointer to the exported memory area, or NULL in case of error.
  */
-void *cucul_export_memory(cucul_canvas_t *cv, char const *format,
+void *cucul_export_memory(cucul_canvas_t const *cv, char const *format,
                           unsigned long int *bytes)
 {
     if(!strcasecmp("caca", format))
@@ -155,7 +155,7 @@ char const * const * cucul_get_export_list(void)
  */
 
 /* Generate a native libcaca canvas file. */
-static void *export_caca(cucul_canvas_t *cv, unsigned long int *bytes)
+static void *export_caca(cucul_canvas_t const *cv, unsigned long int *bytes)
 {
     uint32_t *attrs = cv->attrs;
     uint32_t *chars = cv->chars;
@@ -201,7 +201,8 @@ static void *export_caca(cucul_canvas_t *cv, unsigned long int *bytes)
 }
 
 /* Generate UTF-8 representation of current canvas. */
-static void *export_utf8(cucul_canvas_t *cv, unsigned long int *bytes, int cr)
+static void *export_utf8(cucul_canvas_t const *cv, unsigned long int *bytes,
+                         int cr)
 {
     static uint8_t const palette[] =
     {
@@ -281,7 +282,7 @@ static void *export_utf8(cucul_canvas_t *cv, unsigned long int *bytes, int cr)
 }
 
 /* Generate ANSI representation of current canvas. */
-static void *export_ansi(cucul_canvas_t *cv, unsigned long int *bytes)
+static void *export_ansi(cucul_canvas_t const *cv, unsigned long int *bytes)
 {
     static uint8_t const palette[] =
     {
@@ -361,7 +362,7 @@ static void *export_ansi(cucul_canvas_t *cv, unsigned long int *bytes)
 }
 
 /* Generate HTML representation of current canvas. */
-static void *export_html(cucul_canvas_t *cv, unsigned long int *bytes)
+static void *export_html(cucul_canvas_t const *cv, unsigned long int *bytes)
 {
     char *data, *cur;
     unsigned int x, y, len;
@@ -443,7 +444,7 @@ static void *export_html(cucul_canvas_t *cv, unsigned long int *bytes)
  * but permits viewing in old browsers (or limited ones such as links). It
  * will not work under gecko (mozilla rendering engine) unless you set a
  * correct header. */
-static void *export_html3(cucul_canvas_t *cv, unsigned long int *bytes)
+static void *export_html3(cucul_canvas_t const *cv, unsigned long int *bytes)
 {
     char *data, *cur;
     unsigned int x, y, len;
@@ -545,7 +546,7 @@ static void *export_html3(cucul_canvas_t *cv, unsigned long int *bytes)
 }
 
 /* Export a text file with IRC colours */
-static void *export_irc(cucul_canvas_t *cv, unsigned long int *bytes)
+static void *export_irc(cucul_canvas_t const *cv, unsigned long int *bytes)
 {
     static uint8_t const palette[] =
     {
@@ -652,7 +653,7 @@ static void *export_irc(cucul_canvas_t *cv, unsigned long int *bytes)
 }
 
 /* Export a PostScript document. */
-static void *export_ps(cucul_canvas_t *cv, unsigned long int *bytes)
+static void *export_ps(cucul_canvas_t const *cv, unsigned long int *bytes)
 {
     static char const *ps_header =
         "%!\n"
@@ -761,7 +762,7 @@ static void *export_ps(cucul_canvas_t *cv, unsigned long int *bytes)
 }
 
 /* Export an SVG vector image */
-static void *export_svg(cucul_canvas_t *cv, unsigned long int *bytes)
+static void *export_svg(cucul_canvas_t const *cv, unsigned long int *bytes)
 {
     static char const svg_header[] =
         "<?xml version=\"1.0\" encoding=\"UTF-8\"?>\n"
@@ -847,7 +848,7 @@ static void *export_svg(cucul_canvas_t *cv, unsigned long int *bytes)
 }
 
 /* Export a TGA image */
-static void *export_tga(cucul_canvas_t *cv, unsigned long int *bytes)
+static void *export_tga(cucul_canvas_t const *cv, unsigned long int *bytes)
 {
     char const * const *fontlist;
     char *data, *cur;
diff --git a/cucul/font.c b/cucul/font.c
index f981a6e..02cede5 100644
--- a/cucul/font.c
+++ b/cucul/font.c
@@ -325,7 +325,7 @@ char const * const * cucul_get_font_list(void)
  *  \param f The font, as returned by cucul_load_font()
  *  \return The standard glyph width.
  */
-unsigned int cucul_get_font_width(cucul_font_t *f)
+unsigned int cucul_get_font_width(cucul_font_t const *f)
 {
     return f->header.width;
 }
@@ -340,7 +340,7 @@ unsigned int cucul_get_font_width(cucul_font_t *f)
  *  \param f The font, as returned by cucul_load_font()
  *  \return The standard glyph height.
  */
-unsigned int cucul_get_font_height(cucul_font_t *f)
+unsigned int cucul_get_font_height(cucul_font_t const *f)
 {
     return f->header.height;
 }
@@ -365,7 +365,7 @@ unsigned int cucul_get_font_height(cucul_font_t *f)
  *  \param f The font, as returned by cucul_load_font()
  *  \return The list of Unicode blocks supported by the font.
  */
-unsigned long int const *cucul_get_font_blocks(cucul_font_t *f)
+unsigned long int const *cucul_get_font_blocks(cucul_font_t const *f)
 {
     return (unsigned long int const *)f->user_block_list;
 }
@@ -415,7 +415,7 @@ int cucul_free_font(cucul_font_t *f)
  *  \param pitch The pitch (in bytes) of an image buffer line.
  *  \return This function always returns 0.
  */
-int cucul_render_canvas(cucul_canvas_t *cv, cucul_font_t *f,
+int cucul_render_canvas(cucul_canvas_t const *cv, cucul_font_t const *f,
                         void *buf, unsigned int width,
                         unsigned int height, unsigned int pitch)
 {
diff --git a/cucul/frame.c b/cucul/frame.c
index 0a2fd84..3d3548c 100644
--- a/cucul/frame.c
+++ b/cucul/frame.c
@@ -37,7 +37,7 @@
  *  \param cv A libcucul canvas
  *  \return The frame count
  */
-unsigned int cucul_get_frame_count(cucul_canvas_t *cv)
+unsigned int cucul_get_frame_count(cucul_canvas_t const *cv)
 {
     return cv->framecount;
 }
@@ -83,7 +83,7 @@ int cucul_set_frame(cucul_canvas_t *cv, unsigned int id)
  *  \param cv A libcucul canvas.
  *  \return The current frame's name.
  */
-char const *cucul_get_frame_name(cucul_canvas_t *cv)
+char const *cucul_get_frame_name(cucul_canvas_t const *cv)
 {
     return cv->frames[cv->frame].name;
 }