diff --git a/clang/lib/Parse/ParseDecl.cpp b/clang/lib/Parse/ParseDecl.cpp
--- a/clang/lib/Parse/ParseDecl.cpp
+++ b/clang/lib/Parse/ParseDecl.cpp
@@ -2827,6 +2827,8 @@
 /// [C++0x] assignment-expression ...[opt]
 ExprResult Parser::ParseAlignArgument(SourceLocation Start,
                                       SourceLocation &EllipsisLoc) {
+  EnterExpressionEvaluationContext ConstantEvaluated(
+      Actions, Sema::ExpressionEvaluationContext::ConstantEvaluated);
   ExprResult ER;
   if (isTypeIdInParens()) {
     SourceLocation TypeLoc = Tok.getLocation();
@@ -2834,8 +2836,9 @@
     SourceRange TypeRange(Start, Tok.getLocation());
     ER = Actions.ActOnUnaryExprOrTypeTraitExpr(TypeLoc, UETT_AlignOf, true,
                                                Ty.getAsOpaquePtr(), TypeRange);
-  } else
-    ER = ParseConstantExpression();
+  } else {
+    ER = ParseConstantExpressionInExprEvalContext();
+  }
 
   if (getLangOpts().CPlusPlus11)
     TryConsumeToken(tok::ellipsis, EllipsisLoc);
diff --git a/clang/test/AST/alignas_maybe_odr_cleanup.cpp b/clang/test/AST/alignas_maybe_odr_cleanup.cpp
new file mode 100644
--- /dev/null
+++ b/clang/test/AST/alignas_maybe_odr_cleanup.cpp
@@ -0,0 +1,15 @@
+// RUN: %clang_cc1 -fsyntax-only %s -ast-dump | FileCheck %s
+
+struct FOO {
+  static const int vec_align_bytes = 32;
+  void foo() {
+    double a alignas(vec_align_bytes);
+    ;
+  }
+};
+
+// CHECK: AlignedAttr {{.*}} alignas
+// CHECK: ConstantExpr {{.+}} 'int' Int: 32
+// CHECK: ImplicitCastExpr {{.*}} 'int' <LValueToRValue>
+// CHECK: DeclRefExpr {{.*}} 'const int' lvalue Var {{.*}} 'vec_align_bytes' 'const int' non_odr_use_constant
+// CHECK: NullStmt