diff --git a/Source/CParse/parser.y b/Source/CParse/parser.y
index 4d4401572..b8691ab9c 100644
--- a/Source/CParse/parser.y
+++ b/Source/CParse/parser.y
@@ -2644,6 +2644,7 @@ template_directive: SWIGTEMPLATE LPAREN idstringopt RPAREN idcolonnt LESSTHAN va
 		  n = Swig_cparse_template_locate($5,$7,tscope);
 
 		  /* Patch the argument types to respect namespaces */
+Printf(stdout, "    p before patching: %s\n", ParmList_str_defaultargs($7));
 		  p = $7;
 		  while (p) {
 		    SwigType *value = Getattr(p,"value");
@@ -2669,6 +2670,7 @@ template_directive: SWIGTEMPLATE LPAREN idstringopt RPAREN idcolonnt LESSTHAN va
 
 		    p = nextSibling(p);
 		  }
+Printf(stdout, "    p after  patching: %s\n", ParmList_str_defaultargs($7));
 
 		  /* Look for the template */
 		  {
@@ -2746,6 +2748,7 @@ template_directive: SWIGTEMPLATE LPAREN idstringopt RPAREN idcolonnt LESSTHAN va
                               def_supplied = 1;
                             }
                           }
+Printf(stdout, "    p tempar patching: %s\n", ParmList_str_defaultargs(temparms));
 
                           templnode = copy_node(nn);
                           /* We need to set the node name based on name used to instantiate */
diff --git a/Source/Swig/parms.c b/Source/Swig/parms.c
index 9b58f5fcb..6b0863ee4 100644
--- a/Source/Swig/parms.c
+++ b/Source/Swig/parms.c
@@ -114,6 +114,14 @@ int ParmList_len(ParmList *p) {
   return i;
 }
 
+/* ---------------------------------------------------------------------
+ * get_empty_type()
+ * ---------------------------------------------------------------------- */
+
+static SwigType *get_empty_type() {
+  return NewStringEmpty();
+}
+
 /* ---------------------------------------------------------------------
  * ParmList_str()
  *
@@ -123,7 +131,8 @@ int ParmList_len(ParmList *p) {
 String *ParmList_str(ParmList *p) {
   String *out = NewStringEmpty();
   while (p) {
-    String *pstr = SwigType_str(Getattr(p, "type"), Getattr(p, "name"));
+    String *type = Getattr(p, "type");
+    String *pstr = SwigType_str(type ? type : get_empty_type(), Getattr(p, "name"));
     Append(out, pstr);
     p = nextSibling(p);
     if (p) {
@@ -144,7 +153,8 @@ String *ParmList_str_defaultargs(ParmList *p) {
   String *out = NewStringEmpty();
   while (p) {
     String *value = Getattr(p, "value");
-    String *pstr = SwigType_str(Getattr(p, "type"), Getattr(p, "name"));
+    String *type = Getattr(p, "type");
+    String *pstr = SwigType_str(type ? type : get_empty_type(), Getattr(p, "name"));
     Append(out, pstr);
     if (value) {
       Printf(out, "=%s", value);
@@ -167,7 +177,8 @@ String *ParmList_str_defaultargs(ParmList *p) {
 String *ParmList_protostr(ParmList *p) {
   String *out = NewStringEmpty();
   while (p) {
-    String *pstr = SwigType_str(Getattr(p, "type"), 0);
+    String *type = Getattr(p, "type");
+    String *pstr = SwigType_str(type ? type : get_empty_type(), 0);
     Append(out, pstr);
     p = nextSibling(p);
     if (p) {