diff --git a/mlir/include/mlir/Support/ToolUtilities.h b/mlir/include/mlir/Support/ToolUtilities.h
index 9a3c05b23a68..b2fcb012b3ee 100644
--- a/mlir/include/mlir/Support/ToolUtilities.h
+++ b/mlir/include/mlir/Support/ToolUtilities.h
@@ -19,7 +19,7 @@
 
 namespace llvm {
 class MemoryBuffer;
-}
+} // namespace llvm
 
 namespace mlir {
 struct LogicalResult;