diff --git a/mlir/lib/Support/ToolUtilities.cpp b/mlir/lib/Support/ToolUtilities.cpp
--- a/mlir/lib/Support/ToolUtilities.cpp
+++ b/mlir/lib/Support/ToolUtilities.cpp
@@ -37,8 +37,8 @@
     auto splitLoc = llvm::SMLoc::getFromPointer(subBuffer.data());
     unsigned splitLine = fileSourceMgr.getLineAndColumn(splitLoc).first;
     auto subMemBuffer = llvm::MemoryBuffer::getMemBufferCopy(
-        subBuffer, origMemBuffer->getBufferIdentifier() +
-                       Twine(" split at line #") + Twine(splitLine));
+        subBuffer,
+        origMemBuffer->getBufferIdentifier() + ":" + Twine(splitLine) + "+");
     if (failed(processChunkBuffer(std::move(subMemBuffer), os)))
       hadFailure = true;
   }