diff --git a/LICENSE b/LICENSE
index 6c4ca5a2c..f0b6e6975 100644
--- a/LICENSE
+++ b/LICENSE
@@ -1,5 +1,5 @@
 The following Apache 2.0 license applies to all code in this package except
-google-java-format-diff.py.
+google_java_format_diff.py.
 
                                  Apache License
                            Version 2.0, January 2004
@@ -205,7 +205,7 @@ google-java-format-diff.py.
 
 ------------------------------------------------------------------------------
 
-The following NCSA license applies only to google-java-format-diff.py.
+The following NCSA license applies only to google_java_format_diff.py.
 
 ==============================================================================
 LLVM Release License
diff --git a/README.md b/README.md
index 38fdac5e8..552d2a364 100644
--- a/README.md
+++ b/README.md
@@ -21,7 +21,7 @@ offsets (`--offset`), passing through to standard-out (default) or altered
 in-place (`--replace`).
 
 To reformat changed lines in a specific patch, use
-[`google-java-format-diff.py`](https://github.com/google/google-java-format/blob/master/scripts/google-java-format-diff.py).
+[`google_java_format_diff.py`](https://github.com/google/google-java-format/blob/master/scripts/google_java_format_diff.py).
 
 ***Note:*** *There is no configurability as to the formatter's algorithm for
 formatting. This is a deliberate design decision to unify our code formatting on
diff --git a/scripts/google-java-format-diff.py b/scripts/google_java_format_diff.py
similarity index 95%
rename from scripts/google-java-format-diff.py
rename to scripts/google_java_format_diff.py
index 7f52ed1ec..9ed255d21 100755
--- a/scripts/google-java-format-diff.py
+++ b/scripts/google_java_format_diff.py
@@ -1,6 +1,6 @@
 #!/usr/bin/env python3
 #
-# ===- google-java-format-diff.py - google-java-format Diff Reformatter -----===#
+# ===- google_java_format_diff.py - google-java-format Diff Reformatter -----===#
 #
 #                     The LLVM Compiler Infrastructure
 #
@@ -17,12 +17,12 @@
 lines. This is useful to reformat all the lines touched by a specific patch.
 Example usage for git/svn users:
 
-  git diff -U0 HEAD^ | google-java-format-diff.py -p1 -i
-  svn diff --diff-cmd=diff -x-U0 | google-java-format-diff.py -i
+  git diff -U0 HEAD^ | google_java_format_diff.py -p1 -i
+  svn diff --diff-cmd=diff -x-U0 | google_java_format_diff.py -i
 
 For perforce users:
 
-  P4DIFF="git --no-pager diff --no-index" p4 diff | ./google-java-format-diff.py -i -p7
+  P4DIFF="git --no-pager diff --no-index" p4 diff | ./google_java_format_diff.py -i -p7
 
 """