diff --git a/src/Makefile.am b/src/Makefile.am
index 5dc8ade..132063f 100644
--- a/src/Makefile.am
+++ b/src/Makefile.am
@@ -24,5 +24,5 @@ if NEED_PIC
 libcaca_pic_a = libcaca_pic.a
 endif
 libcaca_pic_a_SOURCES = $(libcaca_a_SOURCES)
-libcaca_pic_a_CPPFLAGS = -fPIC
+libcaca_pic_a_CPPFLAGS = -fPIC -DPIC
 
diff --git a/src/bitmap.c b/src/bitmap.c
index 403130d..248097e 100644
--- a/src/bitmap.c
+++ b/src/bitmap.c
@@ -160,13 +160,14 @@ static void mask2shift(unsigned int mask, int *right, int *left)
     *left = 12 - lshift;
 }
 
-struct caca_bitmap *caca_create_bitmap(int bpp, int w, int h, int pitch,
-                                       int rmask, int gmask, int bmask,
-                                       int amask)
+struct caca_bitmap *caca_create_bitmap(unsigned int bpp, unsigned int w,
+                                       unsigned int h, unsigned int pitch,
+                                       unsigned int rmask, unsigned int gmask,
+                                       unsigned int bmask, unsigned int amask)
 {
     struct caca_bitmap *bitmap;
 
-    /* Currently only this format is supported. Will improve later. */
+    /* Minor sanity test */
     if(!w || !h || !pitch || bpp > 32 || bpp < 8)
         return NULL;
 
@@ -331,7 +332,7 @@ static void rgb2hsv_default(int r, int g, int b, int *hue, int *sat, int *val)
 }
 
 void caca_draw_bitmap(int x1, int y1, int x2, int y2,
-                      const struct caca_bitmap *bitmap, char *pixels)
+                      const struct caca_bitmap *bitmap, void *pixels)
 {
 #if !NEW_RENDERER
     static const int white_colors[] =
diff --git a/src/caca.c b/src/caca.c
index 2a5d078..56f2630 100644
--- a/src/caca.c
+++ b/src/caca.c
@@ -50,16 +50,8 @@
 
 static void caca_init_terminal(void);
 
-char *_caca_empty_line;
-char *_caca_scratch_line;
-
 #if defined(USE_NCURSES)
 static mmask_t oldmask;
-int _caca_attr[16*16];
-#endif
-
-#if defined(USE_CONIO)
-char *_caca_screen;
 #endif
 
 int caca_init(void)
diff --git a/src/caca.h b/src/caca.h
index 0b22928..f78dff7 100644
--- a/src/caca.h
+++ b/src/caca.h
@@ -212,10 +212,13 @@ void caca_free_sprite(struct caca_sprite *);
  * Bitmap handling
  */
 struct caca_bitmap;
-struct caca_bitmap *caca_create_bitmap(int, int, int, int, int, int, int, int);
+struct caca_bitmap *caca_create_bitmap(unsigned int, unsigned int,
+                                       unsigned int, unsigned int,
+                                       unsigned int, unsigned int,
+                                       unsigned int, unsigned int);
 void caca_set_bitmap_palette(struct caca_bitmap *, unsigned int[],
                              unsigned int[], unsigned int[], unsigned int[]);
-void caca_draw_bitmap(int, int, int, int, const struct caca_bitmap *, char *);
+void caca_draw_bitmap(int, int, int, int, const struct caca_bitmap *, void *);
 void caca_free_bitmap(struct caca_bitmap *);
 
 #ifdef __cplusplus
diff --git a/src/caca_internals.h b/src/caca_internals.h
index ab0b8be..36113ef 100644
--- a/src/caca_internals.h
+++ b/src/caca_internals.h
@@ -32,19 +32,7 @@
 
 extern int _caca_init_graphics(void);
 
-#if defined(USE_NCURSES)
-extern int _caca_attr[];
-#endif
-
-#if defined(USE_CONIO)
-extern struct text_info _ti;
-extern char *_caca_screen;
-#endif
-
 extern unsigned int _caca_width;
 extern unsigned int _caca_height;
 
-extern char *_caca_empty_line;
-extern char *_caca_scratch_line;
-
 #endif /* __CACA_INTERNALS_H__ */
diff --git a/src/graphics.c b/src/graphics.c
index 6de3d3d..e5ebe4c 100644
--- a/src/graphics.c
+++ b/src/graphics.c
@@ -57,12 +57,26 @@
 #include "caca.h"
 #include "caca_internals.h"
 
-#ifdef USE_CONIO
+/*
+ * Global variables
+ */
+unsigned int _caca_width;
+unsigned int _caca_height;
+
+/*
+ * Local variables
+ */
+#if defined(USE_NCURSES)
+static int _caca_attr[16*16];
+#endif
+
+#if defined(USE_CONIO)
 static struct text_info ti;
+static char *_caca_screen;
 #endif
 
-unsigned int _caca_width;
-unsigned int _caca_height;
+static char *_caca_empty_line;
+static char *_caca_scratch_line;
 
 static unsigned int _caca_delay;
 static unsigned int _caca_rendertime;