diff --git a/glib/tests/convert.c b/glib/tests/convert.c
index c43b3db6e..de6c8a73a 100644
--- a/glib/tests/convert.c
+++ b/glib/tests/convert.c
@@ -138,7 +138,7 @@ test_byte_order (void)
 
 static void
 check_utf8_to_ucs4 (const char     *utf8,
-		    glong           utf8_len,
+		    gsize           utf8_len,
 		    const gunichar *ucs4,
 		    glong           ucs4_len,
 		    glong           error_pos)
@@ -292,7 +292,7 @@ check_ucs4_to_utf8 (const gunichar *ucs4,
 
 static void
 check_utf8_to_utf16 (const char      *utf8,
-		     glong            utf8_len,
+		     gsize            utf8_len,
 		     const gunichar2 *utf16,
 		     glong            utf16_len,
 		     glong            error_pos)