diff --git a/cpp/src/arrow/ipc/CMakeLists.txt b/cpp/src/arrow/ipc/CMakeLists.txt
index 2d3eb0f6c589d..2fc9b145ccc98 100644
--- a/cpp/src/arrow/ipc/CMakeLists.txt
+++ b/cpp/src/arrow/ipc/CMakeLists.txt
@@ -6,7 +6,7 @@
 # "License"); you may not use this file except in compliance
 # with the License.  You may obtain a copy of the License at
 #
-# http://www.apache.org/licenses/LICENSE-2.0
+#   http://www.apache.org/licenses/LICENSE-2.0
 #
 # Unless required by applicable law or agreed to in writing,
 # software distributed under the License is distributed on an