diff --git a/libavdevice/opengl_enc.c b/libavdevice/opengl_enc.c
index b2ac6eb..6351614 100644
--- a/libavdevice/opengl_enc.c
+++ b/libavdevice/opengl_enc.c
@@ -116,7 +116,7 @@ typedef void   (APIENTRY *FF_PFNGLATTACHSHADERPROC) (GLuint program, GLuint shad
 typedef GLuint (APIENTRY *FF_PFNGLCREATESHADERPROC) (GLenum type);
 typedef void   (APIENTRY *FF_PFNGLDELETESHADERPROC) (GLuint shader);
 typedef void   (APIENTRY *FF_PFNGLCOMPILESHADERPROC) (GLuint shader);
-typedef void   (APIENTRY *FF_PFNGLSHADERSOURCEPROC) (GLuint shader, GLsizei count, const char* *string, const GLint *length);
+typedef void   (APIENTRY *FF_PFNGLSHADERSOURCEPROC) (GLuint shader, GLsizei count, const char* const *string, const GLint *length);
 typedef void   (APIENTRY *FF_PFNGLGETSHADERIVPROC) (GLuint shader, GLenum pname, GLint *params);
 typedef void   (APIENTRY *FF_PFNGLGETSHADERINFOLOGPROC) (GLuint shader, GLsizei bufSize, GLsizei *length, char *infoLog);