diff --git a/packages/rocketchat-theme/client/imports/components/message-box.css b/packages/rocketchat-theme/client/imports/components/message-box.css
index b6df6d66c05c..6137a678148c 100644
--- a/packages/rocketchat-theme/client/imports/components/message-box.css
+++ b/packages/rocketchat-theme/client/imports/components/message-box.css
@@ -97,6 +97,7 @@
 		width: 100%;
 		max-height: 155px;
 		padding: 0;
+		height: 15px;
 
 		resize: none;