diff --git a/contrib/mklog.py b/contrib/mklog.py
index 674c1dcd78b9665587d877c42df7c6564dbe11ef..ba70af0eef28d1c978027faaf480c65f3577d7f3 100755
--- a/contrib/mklog.py
+++ b/contrib/mklog.py
@@ -38,6 +38,9 @@ import requests
 
 from unidiff import PatchSet
 
+LINE_LIMIT = 100
+TAB_WIDTH = 8
+
 pr_regex = re.compile(r'(\/(\/|\*)|[Cc*!])\s+(?P<pr>PR [a-z+-]+\/[0-9]+)')
 prnum_regex = re.compile(r'PR (?P<comp>[a-z+-]+)/(?P<num>[0-9]+)')
 dr_regex = re.compile(r'(\/(\/|\*)|[Cc*!])\s+(?P<dr>DR [0-9]+)')
@@ -134,6 +137,16 @@ def get_pr_titles(prs):
     return '\n'.join(output)
 
 
+def append_changelog_line(out, relative_path, text):
+    line = f'\t* {relative_path}:'
+    if len(line.replace('\t', ' ' * TAB_WIDTH) + ' ' + text) <= LINE_LIMIT:
+        out += f'{line} {text}\n'
+    else:
+        out += f'{line}\n'
+        out += f'\t{text}\n'
+    return out
+
+
 def generate_changelog(data, no_functions=False, fill_pr_titles=False,
                        additional_prs=None):
     changelogs = {}
@@ -213,12 +226,12 @@ def generate_changelog(data, no_functions=False, fill_pr_titles=False,
             relative_path = file.path[len(changelog):].lstrip('/')
             functions = []
             if file.is_added_file:
-                msg = 'New test' if in_tests else 'New file'
-                out += '\t* %s: %s.\n' % (relative_path, msg)
+                msg = 'New test.' if in_tests else 'New file.'
+                out = append_changelog_line(out, relative_path, msg)
             elif file.is_removed_file:
-                out += '\t* %s: Removed.\n' % (relative_path)
+                out = append_changelog_line(out, relative_path, 'Removed.')
             elif hasattr(file, 'is_rename') and file.is_rename:
-                out += '\t* %s: Moved to...\n' % (relative_path)
+                out = append_changelog_line(out, relative_path, 'Moved to...')
                 new_path = file.target_file[2:]
                 # A file can be theoretically moved to a location that
                 # belongs to a different ChangeLog.  Let user fix it.
@@ -227,6 +240,7 @@ def generate_changelog(data, no_functions=False, fill_pr_titles=False,
                 out += '\t* %s: ...here.\n' % (new_path)
             elif os.path.basename(file.path) in generated_files:
                 out += '\t* %s: Regenerate.\n' % (relative_path)
+                append_changelog_line(out, relative_path, 'Regenerate.')
             else:
                 if not no_functions:
                     for hunk in file:
diff --git a/contrib/test_mklog.py b/contrib/test_mklog.py
index f5e9ecd577c8e95532f8508ca94d31d8358256ba..bf2f280b46e625c3f962483c5517712eca179791 100755
--- a/contrib/test_mklog.py
+++ b/contrib/test_mklog.py
@@ -443,6 +443,27 @@ gcc/ChangeLog:
 
 '''
 
+PATCH10 = '''\
+diff --git a/libgomp/doc/the-libgomp-abi/implementing-firstprivate-lastprivate-copyin-and-copyprivate-clauses.rst b/libgomp/doc/the-libgomp-abi/implementing-firstprivate-lastprivate-copyin-and-copyprivate-clauses.rst
+new file mode 100644
+index 00000000000..ad3c6d856fc
+--- /dev/null
++++ b/libgomp/doc/the-libgomp-abi/implementing-firstprivate-lastprivate-copyin-and-copyprivate-clauses.rst
+@@ -0,0 +1,3 @@
++
++
++
+
+'''
+
+EXPECTED10 = '''\
+libgomp/ChangeLog:
+
+	* doc/the-libgomp-abi/implementing-firstprivate-lastprivate-copyin-and-copyprivate-clauses.rst:
+	New file.
+
+'''
+
 class TestMklog(unittest.TestCase):
     def test_macro_definition(self):
         changelog = generate_changelog(PATCH1)
@@ -485,3 +506,7 @@ class TestMklog(unittest.TestCase):
     def test_define_macro_parsing(self):
         changelog = generate_changelog(PATCH9)
         assert changelog == EXPECTED9
+
+    def test_long_filenames(self):
+        changelog = generate_changelog(PATCH10)
+        assert changelog == EXPECTED10