diff --git a/pixfunplugin.c b/pixfunplugin.c
index ca595ac80340..57522e584bda 100644
--- a/pixfunplugin.c
+++ b/pixfunplugin.c
@@ -42,7 +42,7 @@ extern CPLErr GDALRegisterDefaultPixelFunc();
 /************************************************************************/
 /*                         GDALRegister_PIXFUN()                        */
 /************************************************************************/
-void GDALRegister_PIXFUN()
+void GDALRegister_PIXFUN(void)
 {
     const char PLUGINNAME[]="Pixfun";