diff --git a/CHANGES.md b/CHANGES.md
index 0bd48b18..085311a1 100644
--- a/CHANGES.md
+++ b/CHANGES.md
@@ -4,6 +4,7 @@
 
 - [pull #617] Add MarkdownFileLinks extra (#528)
 - [pull #622] Add missing block tags to regex (#620)
+- [pull #623] Don't escape plus signs in URLs (#621)
 
 
 ## python-markdown2 2.5.3
diff --git a/lib/markdown2.py b/lib/markdown2.py
index a47df6a6..60553e20 100755
--- a/lib/markdown2.py
+++ b/lib/markdown2.py
@@ -4099,8 +4099,6 @@ def _html_escape_url(
         .replace('<', '&lt;')
         .replace('>', '&gt;'))
     if safe_mode:
-        if charset != 'base64':
-            escaped = escaped.replace('+', ' ')
         escaped = escaped.replace("'", "&#39;")
     return escaped
 
diff --git a/test/tm-cases/safe_mode_issue621.html b/test/tm-cases/safe_mode_issue621.html
new file mode 100644
index 00000000..2bd9356b
--- /dev/null
+++ b/test/tm-cases/safe_mode_issue621.html
@@ -0,0 +1 @@
+<p><a href="https://chromium.googlesource.com/v8/v8.git/+/refs/heads/beta">Chromium</a></p>
diff --git a/test/tm-cases/safe_mode_issue621.opts b/test/tm-cases/safe_mode_issue621.opts
new file mode 100644
index 00000000..de64198e
--- /dev/null
+++ b/test/tm-cases/safe_mode_issue621.opts
@@ -0,0 +1 @@
+{'safe_mode': 'escape'}
\ No newline at end of file
diff --git a/test/tm-cases/safe_mode_issue621.text b/test/tm-cases/safe_mode_issue621.text
new file mode 100644
index 00000000..f8c742d4
--- /dev/null
+++ b/test/tm-cases/safe_mode_issue621.text
@@ -0,0 +1 @@
+[Chromium](https://chromium.googlesource.com/v8/v8.git/+/refs/heads/beta)
\ No newline at end of file