diff --git a/unittests/DebugInfo/PDB/BinaryStreamTest.cpp b/unittests/DebugInfo/PDB/BinaryStreamTest.cpp
index b7308868e05..56552d573ce 100644
--- a/unittests/DebugInfo/PDB/BinaryStreamTest.cpp
+++ b/unittests/DebugInfo/PDB/BinaryStreamTest.cpp
@@ -13,7 +13,6 @@
 #include "llvm/DebugInfo/MSF/BinaryStreamReader.h"
 #include "llvm/DebugInfo/MSF/BinaryStreamRef.h"
 #include "llvm/DebugInfo/MSF/BinaryStreamWriter.h"
-#include "llvm/Support/Errc.h"
 #include "gtest/gtest.h"
 
 #include <unordered_map>
@@ -56,8 +55,8 @@ public:
 
   Error readBytes(uint32_t Offset, uint32_t Size,
                   ArrayRef<uint8_t> &Buffer) override {
-    if (Offset + Size > Data.size())
-      return errorCodeToError(make_error_code(llvm::errc::function_not_supported));
+    if (auto EC = checkOffset(Offset, Size))
+      return EC;
     uint32_t S = startIndex(Offset);
     auto Ref = Data.drop_front(S);
     if (Ref.size() >= Size) {
@@ -75,8 +74,8 @@ public:
 
   Error readLongestContiguousChunk(uint32_t Offset,
                                    ArrayRef<uint8_t> &Buffer) override {
-    if (Offset >= Data.size())
-      return errorCodeToError(make_error_code(llvm::errc::function_not_supported));
+    if (auto EC = checkOffset(Offset, 1))
+      return EC;
     uint32_t S = startIndex(Offset);
     Buffer = Data.drop_front(S);
     return Error::success();
@@ -85,8 +84,8 @@ public:
   uint32_t getLength() override { return Data.size(); }
 
   Error writeBytes(uint32_t Offset, ArrayRef<uint8_t> SrcData) override {
-    if (Offset + SrcData.size() > Data.size())
-      return errorCodeToError(make_error_code(llvm::errc::function_not_supported));
+    if (auto EC = checkOffset(Offset, SrcData.size()))
+      return EC;
     if (SrcData.empty())
       return Error::success();