diff --git a/src/vim9execute.c b/src/vim9execute.c
index e52df61..9bfec3a 100644
--- a/src/vim9execute.c
+++ b/src/vim9execute.c
@@ -723,7 +723,10 @@
 	dfunc_T	*dfunc = ((dfunc_T *)def_functions.ga_data)
 							 + ufunc->uf_dfunc_idx;
 	if (dfunc->df_instr == NULL)
+	{
+	    iemsg("using call_def_function() on not compiled function");
 	    return FAIL;
+	}
     }
 
     CLEAR_FIELD(ectx);
@@ -1726,6 +1729,15 @@
 		}
 		break;
 
+	    // Create a global function from a lambda.
+	    case ISN_NEWFUNC:
+		{
+		    newfunc_T	*newfunc = &iptr->isn_arg.newfunc;
+
+		    copy_func(newfunc->nf_lambda, newfunc->nf_global);
+		}
+		break;
+
 	    // jump if a condition is met
 	    case ISN_JUMP:
 		{
@@ -2912,6 +2924,15 @@
 		}
 		break;
 
+	    case ISN_NEWFUNC:
+		{
+		    newfunc_T	*newfunc = &iptr->isn_arg.newfunc;
+
+		    smsg("%4d NEWFUNC %s %s", current,
+				       newfunc->nf_lambda, newfunc->nf_global);
+		}
+		break;
+
 	    case ISN_JUMP:
 		{
 		    char *when = "?";