Index: generic/nsf.c
===================================================================
diff -u -rf9bd043ef944ad48d9d626408d25d8df241d834d -re75f57c39bdc5455b65317013ed58d2db8d22dbd
--- generic/nsf.c	(.../nsf.c)	(revision f9bd043ef944ad48d9d626408d25d8df241d834d)
+++ generic/nsf.c	(.../nsf.c)	(revision e75f57c39bdc5455b65317013ed58d2db8d22dbd)
@@ -12085,7 +12085,7 @@
     NsfParamDefs *paramDefs = procPtr ? ParamDefsGet((Tcl_Command)procPtr->cmdPtr) : NULL;
     Tcl_Obj *list;
 
-    if (paramDefs) {
+    if (paramDefs && paramDefs->paramsPtr) {
       /*
        * Obtain parameter info from paramDefs
        */