diff --git a/clang/include/clang/AST/Expr.h b/clang/include/clang/AST/Expr.h
index 8a80803f01c2..0f325bdcc915 100644
--- a/clang/include/clang/AST/Expr.h
+++ b/clang/include/clang/AST/Expr.h
@@ -4233,7 +4233,7 @@ public:
   }
 
   /// getFunctionType - Return the underlying function type for this block.
-  const FunctionType *getFunctionType() const;
+  const FunctionProtoType *getFunctionType() const;
 
   static bool classof(const Stmt *T) {
     return T->getStmtClass() == BlockExprClass;
diff --git a/clang/lib/AST/Expr.cpp b/clang/lib/AST/Expr.cpp
index 4b19031852c6..d5eab77816c6 100644
--- a/clang/lib/AST/Expr.cpp
+++ b/clang/lib/AST/Expr.cpp
@@ -1512,9 +1512,10 @@ SourceRange InitListExpr::getSourceRange() const {
 
 /// getFunctionType - Return the underlying function type for this block.
 ///
-const FunctionType *BlockExpr::getFunctionType() const {
-  return getType()->getAs<BlockPointerType>()->
-                    getPointeeType()->getAs<FunctionType>();
+const FunctionProtoType *BlockExpr::getFunctionType() const {
+  // The block pointer is never sugared, but the function type might be.
+  return cast<BlockPointerType>(getType())
+           ->getPointeeType()->castAs<FunctionProtoType>();
 }
 
 SourceLocation BlockExpr::getCaretLocation() const {