diff --git a/ttf.d b/ttf.d
index 300d4f2..c25b065 100644
--- a/ttf.d
+++ b/ttf.d
@@ -1201,7 +1201,7 @@ static void stbtt__rasterize_sorted_edges(stbtt__bitmap *result, stbtt__edge *e,
       STBTT_free(scanline, userdata);
 }
 
-extern(C) int stbtt__edge_compare(const void *p, const void *q)
+extern(C) int stbtt__edge_compare(scope const void *p, scope const void *q)
 {
    stbtt__edge *a = cast(stbtt__edge *) p;
    stbtt__edge *b = cast(stbtt__edge *) q;