diff --git a/src/gui_gtk.c b/src/gui_gtk.c
index 126eaf0..8537060 100644
--- a/src/gui_gtk.c
+++ b/src/gui_gtk.c
@@ -559,7 +559,7 @@
 	if (*psrc == '_')
 	    ++n_underscores;
 
-    buf = alloc((unsigned)(psrc - name + n_underscores + 1));
+    buf = alloc(psrc - name + n_underscores + 1);
     if (buf != NULL)
     {
 	pdest = buf;