diff --git a/pipi/filter/convolution.c b/pipi/filter/convolution.c
index c28a461..604d696 100644
--- a/pipi/filter/convolution.c
+++ b/pipi/filter/convolution.c
@@ -33,11 +33,6 @@
 #define SET_FLAG_GRAY 0x01
 #define SET_FLAG_WRAP 0x02
 
-static pipi_image_t *conv_std_rgba_f(pipi_image_t *src,
-                                     int m, int n, double mat[]);
-static pipi_image_t *conv_sep_rgba_f(pipi_image_t *src,
-                                     int m, double hvec[],
-                                     int n, double vvec[]);
 #undef FUNC1
 #undef FUNC2
 #undef PIXEL
@@ -48,11 +43,6 @@ static pipi_image_t *conv_sep_rgba_f(pipi_image_t *src,
 #define FLAGS 0
 #include "convolution_template.h"
 
-static pipi_image_t *conv_std_y_f(pipi_image_t *src,
-                                  int m, int n, double mat[]);
-static pipi_image_t *conv_sep_y_f(pipi_image_t *src,
-                                  int m, double hvec[],
-                                  int n, double vvec[]);
 #undef FUNC1
 #undef FUNC2
 #undef PIXEL
@@ -63,11 +53,6 @@ static pipi_image_t *conv_sep_y_f(pipi_image_t *src,
 #define FLAGS SET_FLAG_GRAY
 #include "convolution_template.h"
 
-static pipi_image_t *wrap_std_rgba_f(pipi_image_t *src,
-                                     int m, int n, double mat[]);
-static pipi_image_t *wrap_sep_rgba_f(pipi_image_t *src,
-                                     int m, double hvec[],
-                                     int n, double vvec[]);
 #undef FUNC1
 #undef FUNC2
 #undef PIXEL
@@ -78,11 +63,6 @@ static pipi_image_t *wrap_sep_rgba_f(pipi_image_t *src,
 #define FLAGS SET_FLAG_WRAP
 #include "convolution_template.h"
 
-static pipi_image_t *wrap_std_y_f(pipi_image_t *src,
-                                  int m, int n, double mat[]);
-static pipi_image_t *wrap_sep_y_f(pipi_image_t *src,
-                                  int m, double hvec[],
-                                  int n, double vvec[]);
 #undef FUNC1
 #undef FUNC2
 #undef PIXEL
diff --git a/pipi/filter/convolution_template.h b/pipi/filter/convolution_template.h
index 2dd6a62..976fd9b 100644
--- a/pipi/filter/convolution_template.h
+++ b/pipi/filter/convolution_template.h
@@ -22,6 +22,10 @@
  *          2 (loop)
  */
 
+static pipi_image_t *FUNC1(pipi_image_t *src, int m, int n, double mat[]);
+static pipi_image_t *FUNC2(pipi_image_t *src, int m, double hvec[],
+                                              int n, double vvec[]);
+
 static pipi_image_t *FUNC1(pipi_image_t *src, int m, int n, double mat[])
 {
     pipi_image_t *dst;