diff --git a/src/post_modules/GTK/build_pgtk.pike b/src/post_modules/GTK/build_pgtk.pike
index a66dd6638d40c277f159d7d6072933187366ba7a..47639f2d2e8dc1328853c1a74473d6e45762e5f2 100755
--- a/src/post_modules/GTK/build_pgtk.pike
+++ b/src/post_modules/GTK/build_pgtk.pike
@@ -1392,7 +1392,8 @@ void do_default_sprintf( int args, int offset, int len )
 	      post += ("  if (_arg"+na+"->size != "+
 		       (t=replace(t,({"{","}"}),({"(",")"})))+
 		       ") \n"
-		       "    error(\"argument "+na+" (array(string)) has wrong size (columns=%d, elements=%d)\\n\","+t+",_arg"+na+"->size);"
+		       "    error(\"argument "+na+" (array(string)) has wrong size (columns=%d, elements=%d)\\n\",\n"
+		       "          "+t+",_arg"+na+"->size);\n"
 		       "  arg"+na+"=alloca(sizeof(char *)* (_arg"+na+"->size));\n"
 		       "  for(_i=0; _i<_arg"+na+"->size; _i++)\n"
 		       "  {\n"