diff --git a/DOCUMENTATION.md b/DOCUMENTATION.md
index 0d0ab6cd..6e7b7c69 100644
--- a/DOCUMENTATION.md
+++ b/DOCUMENTATION.md
@@ -427,6 +427,9 @@ RewriteRule ^/radicale$ /radicale/ [R,L]
     RequestHeader    set X-Script-Name /radicale
     RequestHeader    set X-Forwarded-Port "%{SERVER_PORT}s"
     RequestHeader    set X-Forwarded-Proto expr=%{REQUEST_SCHEME}
+    <IfVersion >= 2.4.40>
+    Proxy100Continue Off
+    </IfVersion>
 </Location>
 ```
 
@@ -517,6 +520,9 @@ RewriteRule ^/radicale$ /radicale/ [R,L]
 
     ProxyPass        http://localhost:5232/ retry=0
     ProxyPassReverse http://localhost:5232/
+    <IfVersion >= 2.4.40>
+    Proxy100Continue Off
+    </IfVersion>
     RequestHeader    set X-Script-Name /radicale
     RequestHeader    set X-Remote-User expr=%{REMOTE_USER}
 </Location>
diff --git a/contrib/apache/radicale.conf b/contrib/apache/radicale.conf
index d92c5c31..385ee159 100644
--- a/contrib/apache/radicale.conf
+++ b/contrib/apache/radicale.conf
@@ -59,6 +59,9 @@
 
 		ProxyPass        http://localhost:5232/ retry=0
 		ProxyPassReverse http://localhost:5232/
+		<IfVersion >= 2.4.40>
+		Proxy100Continue Off
+		</IfVersion>
 
 		Require local
 		<IfDefine RADICALE_PERMIT_PUBLIC_ACCESS>
@@ -74,6 +77,9 @@
 
 		ProxyPass        http://localhost:5232/ retry=0
 		ProxyPassReverse http://localhost:5232/
+		<IfVersion >= 2.4.40>
+		Proxy100Continue Off
+		</IfVersion>
 
 		<IfDefine !RADICALE_SERVER_USER_AUTHENTICATION>
 			## User authentication handled by "radicale"
@@ -221,6 +227,9 @@ CustomLog logs/ssl_request_log "%t %h %{SSL_PROTOCOL}x %{SSL_CIPHER}x \"%r\" %b"
 
 		ProxyPass        http://localhost:5232/ retry=0
 		ProxyPassReverse http://localhost:5232/
+		<IfVersion >= 2.4.40>
+		Proxy100Continue Off
+		</IfVersion>
 
 		Require local
 		<IfDefine RADICALE_PERMIT_PUBLIC_ACCESS>
@@ -234,6 +243,9 @@ CustomLog logs/ssl_request_log "%t %h %{SSL_PROTOCOL}x %{SSL_CIPHER}x \"%r\" %b"
 
 		ProxyPass        http://localhost:5232/ retry=0
 		ProxyPassReverse http://localhost:5232/
+		<IfVersion >= 2.4.40>
+		Proxy100Continue Off
+		</IfVersion>
 
 		<IfDefine !RADICALE_SERVER_USER_AUTHENTICATION>
 			## User authentication handled by "radicale"