diff --git a/src/sna/sna_glyphs.c b/src/sna/sna_glyphs.c
index 1ce71702..e3e865be 100644
--- a/src/sna/sna_glyphs.c
+++ b/src/sna/sna_glyphs.c
@@ -352,7 +352,7 @@ glyph_extents(int nlist,
 }
 
 #if HAS_DEBUG_FULL
-static void
+static int
 glyph_count(int nlist,
 	    GlyphListPtr list)
 {