diff --git a/compiler/semexprs.nim b/compiler/semexprs.nim
index 10ae49b12d..504a548134 100644
--- a/compiler/semexprs.nim
+++ b/compiler/semexprs.nim
@@ -1538,6 +1538,8 @@ proc semAsgn(c: PContext, n: PNode; mode=asgnNormal): PNode =
   # a = b # both are vars, means: a[] = b[]
   # a = b # b no 'var T' means: a = addr(b)
   var le = a.typ
+  if le == nil:
+    localError(c.config, a.info, "expression has no type")
   if (skipTypes(le, {tyGenericInst, tyAlias, tySink}).kind != tyVar and
         isAssignable(c, a) == arNone) or
       skipTypes(le, abstractVar).kind in {tyOpenArray, tyVarargs}: