diff --git a/fluid/fluid.cxx b/fluid/fluid.cxx
index 78c23675553e0c21fd1f48cb1d45e39d72f15f35..8db15bfca5d0c6423b8909e0ff0556cd6392522f 100644
--- a/fluid/fluid.cxx
+++ b/fluid/fluid.cxx
@@ -1699,6 +1699,7 @@ void set_modflag(int mf) {
 ////////////////////////////////////////////////////////////////
 
 static int arg(int argc, char** argv, int& i) {
+  if (argv[i][1] == 'd' && !argv[i][2]) {G_debug=1; i++; return 1;}
   if (argv[i][1] == 'u' && !argv[i][2]) {update_file++; batch_mode++; i++; return 1;}
   if (argv[i][1] == 'c' && !argv[i][2]) {compile_file++; batch_mode++; i++; return 1;}
   if (argv[i][1] == 'c' && argv[i][2] == 's' && !argv[i][3]) {compile_file++; compile_strings++; batch_mode++; i++; return 1;}
@@ -1756,7 +1757,8 @@ int main(int argc,char **argv) {
       " -c : write .cxx and .h and exit\n"
       " -cs : write .cxx and .h and strings and exit\n"
       " -o <name> : .cxx output filename, or extension if <name> starts with '.'\n"
-      " -h <name> : .h output filename, or extension if <name> starts with '.'\n";
+      " -h <name> : .h output filename, or extension if <name> starts with '.'\n"
+      " -d : enable internal debugging\n";
       int len = (int)(strlen(msg) + strlen(argv[0]?argv[0]:"fluid") + strlen(Fl::help));
     Fl_Plugin_Manager pm("commandline");
     int i, n = pm.plugins();