diff --git a/vncviewer/fltk_layout.h b/vncviewer/fltk_layout.h
index 21fb00a..9e5c2d4 100644
--- a/vncviewer/fltk_layout.h
+++ b/vncviewer/fltk_layout.h
@@ -35,9 +35,9 @@
 }
 
 /* Escapes all @ in text as those have special meaning in labels */
-static inline int fltk_escape(const char *in, char *out, size_t maxlen)
+static inline size_t fltk_escape(const char *in, char *out, size_t maxlen)
 {
-    int len;
+    size_t len;
 
     len = 0;
 
@@ -69,9 +69,9 @@
 }
 
 /* Filter out unsafe characters for menu entries */
-static inline int fltk_menu_escape(const char *in, char *out, size_t maxlen)
+static inline size_t fltk_menu_escape(const char *in, char *out, size_t maxlen)
 {
-    int len;
+    size_t len;
 
     len = 0;