diff --git a/src/eval.c b/src/eval.c
index 590834f..5f05c3d 100644
--- a/src/eval.c
+++ b/src/eval.c
@@ -21608,6 +21608,7 @@
 	    case VAR_FLOAT:
 #endif
 	    case VAR_UNKNOWN:
+	    case VAR_SPECIAL:
 		break;
 	    default:
 		EMSG2(_(e_intern2), "free_tv()");