diff --git a/tshark.c b/tshark.c
index bcf1e726e6..df50bc44f0 100644
--- a/tshark.c
+++ b/tshark.c
@@ -193,8 +193,8 @@ struct string_elem {
 static gint
 string_compare(gconstpointer a, gconstpointer b)
 {
-  return strcmp(((struct string_elem *)a)->sstr,
-                ((struct string_elem *)b)->sstr);
+  return strcmp(((const struct string_elem *)a)->sstr,
+                ((const struct string_elem *)b)->sstr);
 }
 
 static void