Index: lib/DebugInfo/CodeView/ModuleDebugFileChecksumFragment.cpp
===================================================================
--- lib/DebugInfo/CodeView/ModuleDebugFileChecksumFragment.cpp
+++ lib/DebugInfo/CodeView/ModuleDebugFileChecksumFragment.cpp
@@ -83,6 +83,7 @@
 }
 
 Error ModuleDebugFileChecksumFragment::commit(BinaryStreamWriter &Writer) {
+  auto StartingOffset = Writer.getOffset();
   for (const auto &FC : Checksums) {
     FileChecksumEntryHeader Header;
     Header.ChecksumKind = uint8_t(FC.Kind);
@@ -92,8 +93,13 @@
       return EC;
     if (auto EC = Writer.writeArray(makeArrayRef(FC.Checksum)))
       return EC;
-    if (auto EC = Writer.padToAlignment(4))
-      return EC;
+    auto Offset = Writer.getOffset();
+    auto Padding = 4 - ((Offset - StartingOffset) % 4);
+    if (Padding < 4) {
+      Offset += Padding;
+      Writer.setOffset(Offset);
+    }
+    StartingOffset = Offset;
   }
   return Error::success();
 }
Index: lib/DebugInfo/CodeView/ModuleDebugFragmentRecord.cpp
===================================================================
--- lib/DebugInfo/CodeView/ModuleDebugFragmentRecord.cpp
+++ lib/DebugInfo/CodeView/ModuleDebugFragmentRecord.cpp
@@ -69,16 +69,19 @@
 
 Error ModuleDebugFragmentRecordBuilder::commit(BinaryStreamWriter &Writer) {
   ModuleDebugFragmentHeader Header;
+  auto SerializedLength = calculateSerializedLength();
+  auto ExpectedOffset = Writer.getOffset() + SerializedLength;
   Header.Kind = uint32_t(Kind);
-  Header.Length =
-      calculateSerializedLength() - sizeof(ModuleDebugFragmentHeader);
+  Header.Length = SerializedLength - sizeof(ModuleDebugFragmentHeader);
 
   if (auto EC = Writer.writeObject(Header))
     return EC;
   if (auto EC = Frag.commit(Writer))
     return EC;
-  if (auto EC = Writer.padToAlignment(4))
-    return EC;
+  // Pad if necessary.
+  if (ExpectedOffset > Writer.getOffset())
+    Writer.setOffset(ExpectedOffset);
+  assert(Writer.getOffset() == ExpectedOffset);
 
   return Error::success();
 }