diff --git a/dlls/winemac.drv/opengl.c b/dlls/winemac.drv/opengl.c
index 4766bd4f3c93a8f97f578ea04a345020b18d7833..ad520fab7a4e523dd316c1caf80ef8f973ffdf50 100644
--- a/dlls/winemac.drv/opengl.c
+++ b/dlls/winemac.drv/opengl.c
@@ -1192,7 +1192,7 @@ static const pixel_format *get_pixel_format(int format, BOOL allow_nondisplayabl
 
 static BOOL init_gl_info(void)
 {
-    static char legacy_extensions[] = " WGL_EXT_extensions_string";
+    static const char legacy_extensions[] = " WGL_EXT_extensions_string";
     static const char legacy_ext_swap_control[] = " WGL_EXT_swap_control";
 
     CGDirectDisplayID display = CGMainDisplayID();