diff --git a/changelogs/fragments/10796-rocketchat-force-content-type.yml b/changelogs/fragments/10796-rocketchat-force-content-type.yml
new file mode 100644
index 0000000000..96ca116e62
--- /dev/null
+++ b/changelogs/fragments/10796-rocketchat-force-content-type.yml
@@ -0,0 +1,2 @@
+bugfixes:
+  - rocketchat - fix message delivery in Rocket Chat >= 7.5.3 by forcing ``Content-Type`` header to ``application/json`` instead of the default ``application/x-www-form-urlencoded`` (https://github.com/ansible-collections/community.general/issues/10796, https://github.com/ansible-collections/community.general/pull/10796).
diff --git a/plugins/modules/rocketchat.py b/plugins/modules/rocketchat.py
index 79dbaa77f2..bd3862ac0a 100644
--- a/plugins/modules/rocketchat.py
+++ b/plugins/modules/rocketchat.py
@@ -202,14 +202,17 @@ def build_payload_for_rocketchat(module, text, channel, username, icon_url, icon
     return payload
 
 
-def do_notify_rocketchat(module, domain, token, protocol, payload):
+def do_notify_rocketchat(module, domain, token, protocol, payload, is_pre740):
 
     if token.count('/') < 1:
         module.fail_json(msg="Invalid Token specified, provide a valid token")
 
     rocketchat_incoming_webhook = ROCKETCHAT_INCOMING_WEBHOOK % (protocol, domain, token)
 
-    response, info = fetch_url(module, rocketchat_incoming_webhook, data=payload)
+    headers = None
+    if not is_pre740:
+        headers = {'Content-type': 'application/json'}
+    response, info = fetch_url(module, rocketchat_incoming_webhook, data=payload, headers=headers)
     if info['status'] != 200:
         module.fail_json(msg="failed to send message, return status=%s" % str(info['status']))
 
@@ -256,7 +259,7 @@ def main():
         is_pre740 = True
 
     payload = build_payload_for_rocketchat(module, text, channel, username, icon_url, icon_emoji, link_names, color, attachments, is_pre740)
-    do_notify_rocketchat(module, domain, token, protocol, payload)
+    do_notify_rocketchat(module, domain, token, protocol, payload, is_pre740)
 
     module.exit_json(msg="OK")