diff --git a/utils/geometry.c b/utils/geometry.c
index b5b06503..7b4a4924 100644
--- a/utils/geometry.c
+++ b/utils/geometry.c
@@ -403,7 +403,7 @@ GeoNameToPos(name, manhattan, verbose)
 	{"west",	GEO_WEST,		TRUE},
 	{0}
     };
-    char *fmt;
+    const char *fmt;
     const struct pos *pp;
     int pos;