diff --git a/src/frontend/subckt.c b/src/frontend/subckt.c
index 1b4dfd5f9..278f510d6 100644
--- a/src/frontend/subckt.c
+++ b/src/frontend/subckt.c
@@ -1995,6 +1995,10 @@ devmodtranslate(struct line *deck, char *subname, wordlist * const submod)
                     (void) sprintf(buffer + strlen(buffer), "%s ", name);
                     tfree(name);
                     name = gettok(&t);
+                    if (name == NULL) {
+                        name = copy(""); /* allow 'tfree' */
+                        break;
+                    }
                 }
             }  /* while  */