diff --git a/historic/jam/src/builtins.c b/historic/jam/src/builtins.c
index 20d413b7c..30aa649ad 100644
--- a/historic/jam/src/builtins.c
+++ b/historic/jam/src/builtins.c
@@ -937,6 +937,17 @@ static void add_hash_key( void* np, void* result_ )
     *result = list_new( *result, copystr( *(char**)np ) );
 }
 
+static struct hash *get_running_module_vars()
+{
+    struct hash *dummy, *vars = NULL;
+    /* Get the global variables pointer (that of the currently running module) */
+    var_hash_swap(&vars);
+    dummy = vars;
+    /* Put the global variables pointer in its right place */
+    var_hash_swap(&dummy);
+    return vars;
+}
+
 LIST *
 builtin_varnames(
     PARSE   *parse,
@@ -946,8 +957,14 @@ builtin_varnames(
     LIST *result = L0;
     module_t* source_module = bindmodule( arg0 ? arg0->string : 0 );
 
-    if ( source_module->variables )
-        hashenumerate( source_module->variables, add_hash_key, &result );
+    /* The running module _always_ has its 'variables' member set to NULL
+     * due to the way enter_module and var_hash_swap work */
+    struct hash *vars = 
+        source_module == frame->module ? 
+            get_running_module_vars() : source_module->variables;
+
+    if ( vars )
+        hashenumerate( vars, add_hash_key, &result );
     return result;
 }