diff --git a/.pre-commit-config.yaml b/.pre-commit-config.yaml
index 87e4564..3386673 100644
--- a/.pre-commit-config.yaml
+++ b/.pre-commit-config.yaml
@@ -4,6 +4,7 @@ repos:
     hooks:
     -   id: trailing-whitespace
     -   id: end-of-file-fixer
+        exclude: testing/resources/pretty_formatted_json_no_endline.json
     -   id: check-yaml
     -   id: debug-statements
     -   id: double-quote-string-fixer
diff --git a/pre_commit_hooks/pretty_format_json.py b/pre_commit_hooks/pretty_format_json.py
index 627a11c..de26839 100644
--- a/pre_commit_hooks/pretty_format_json.py
+++ b/pre_commit_hooks/pretty_format_json.py
@@ -27,7 +27,8 @@ def _get_pretty_format(
         indent=indent,
         ensure_ascii=ensure_ascii,
     )
-    return f'{json_pretty}\n'
+    finisher = '\n' if contents.endswith('\n') else ''
+    return f'{json_pretty}{finisher}'
 
 
 def _autofix(filename: str, new_contents: str) -> None:
diff --git a/testing/resources/pretty_formatted_json_no_endline.json b/testing/resources/pretty_formatted_json_no_endline.json
new file mode 100644
index 0000000..170c74a
--- /dev/null
+++ b/testing/resources/pretty_formatted_json_no_endline.json
@@ -0,0 +1,9 @@
+{
+  "alist": [
+    2,
+    34,
+    234
+  ],
+  "blah": null,
+  "foo": "bar"
+}
\ No newline at end of file
diff --git a/tests/pretty_format_json_test.py b/tests/pretty_format_json_test.py
index 5ded724..d93db75 100644
--- a/tests/pretty_format_json_test.py
+++ b/tests/pretty_format_json_test.py
@@ -23,6 +23,7 @@ def test_parse_num_to_int():
         ('unsorted_pretty_formatted_json.json', 1),
         ('non_ascii_pretty_formatted_json.json', 1),
         ('pretty_formatted_json.json', 0),
+        ('pretty_formatted_json_no_endline.json', 0),
     ),
 )
 def test_main(filename, expected_retval):
@@ -36,6 +37,7 @@ def test_main(filename, expected_retval):
         ('unsorted_pretty_formatted_json.json', 0),
         ('non_ascii_pretty_formatted_json.json', 1),
         ('pretty_formatted_json.json', 0),
+        ('pretty_formatted_json_no_endline.json', 0),
     ),
 )
 def test_unsorted_main(filename, expected_retval):
@@ -49,6 +51,7 @@ def test_unsorted_main(filename, expected_retval):
         ('unsorted_pretty_formatted_json.json', 1),
         ('non_ascii_pretty_formatted_json.json', 1),
         ('pretty_formatted_json.json', 1),
+        ('pretty_formatted_json_no_endline.json', 1),
         ('tab_pretty_formatted_json.json', 0),
     ),
 )