diff --git a/src/fclist.c b/src/fclist.c
index 414af11..5468b2a 100644
--- a/src/fclist.c
+++ b/src/fclist.c
@@ -80,7 +80,8 @@ FcObjectSetAdd (FcObjectSet *os, const char *object)
     }
     if (c < 0)
 	mid++;
-    memmove (os->objects + mid + 1, os->objects + mid, os->nobject - mid);
+    memmove (os->objects + mid + 1, os->objects + mid, 
+	     (os->nobject - mid) * sizeof (const char *));
     os->objects[mid] = object;
     os->nobject++;
     return FcTrue;