diff --git a/lib/AST/ExprConstant.cpp b/lib/AST/ExprConstant.cpp
index a0b2aa9..382bfe5 100644
--- a/lib/AST/ExprConstant.cpp
+++ b/lib/AST/ExprConstant.cpp
@@ -878,6 +878,10 @@
   // In C, they can also be folded, although they are not ICEs.
   if (Info.Ctx.getCanonicalType(E->getType()).getCVRQualifiers() 
                                                         == Qualifiers::Const) {
+
+    if (isa<ParmVarDecl>(D))
+      return Error(E->getLocStart(), diag::note_invalid_subexpr_in_ice, E);
+
     if (const VarDecl *VD = dyn_cast<VarDecl>(D)) {
       if (const Expr *Init = VD->getAnyInitializer()) {
         if (APValue *V = VD->getEvaluatedValue()) {