diff --git a/dlls/wined3d/shader.c b/dlls/wined3d/shader.c
index 79a27595f02..d0d8d086ec6 100644
--- a/dlls/wined3d/shader.c
+++ b/dlls/wined3d/shader.c
@@ -1706,7 +1706,7 @@ static BOOL match_usage(BYTE usage1, BYTE usage_idx1, BYTE usage2, BYTE usage_id
     return FALSE;
 }
 
-BOOL vshader_get_input(struct wined3d_shader *shader,
+BOOL vshader_get_input(const struct wined3d_shader *shader,
         BYTE usage_req, BYTE usage_idx_req, unsigned int *regnum)
 {
     WORD map = shader->reg_maps.input_registers;
diff --git a/dlls/wined3d/wined3d_private.h b/dlls/wined3d/wined3d_private.h
index f104a195a2b..b9595432000 100644
--- a/dlls/wined3d/wined3d_private.h
+++ b/dlls/wined3d/wined3d_private.h
@@ -2558,7 +2558,7 @@ int shader_addline(struct wined3d_shader_buffer *buffer, const char *fmt, ...) P
 int shader_vaddline(struct wined3d_shader_buffer *buffer, const char *fmt, va_list args) DECLSPEC_HIDDEN;
 
 /* Vertex shader utility functions */
-extern BOOL vshader_get_input(struct wined3d_shader *shader,
+BOOL vshader_get_input(const struct wined3d_shader *shader,
         BYTE usage_req, BYTE usage_idx_req, unsigned int *regnum) DECLSPEC_HIDDEN;
 
 struct wined3d_vertex_shader