diff --git a/chat/modules/imContentSink.jsm b/chat/modules/imContentSink.jsm
index d6ff224da2..4ebc5e7b6f 100644
--- a/chat/modules/imContentSink.jsm
+++ b/chat/modules/imContentSink.jsm
@@ -102,7 +102,7 @@ const kStandardMode = {
   styles: {
     'font-style': true,
     'font-weight': true,
-    '-moz-text-decoration-line': true
+    'text-decoration-line': true
   }
 };
 
@@ -150,9 +150,9 @@ const kPermissiveMode = {
     'font-size': true,
     'font-style': true,
     'font-weight': true,
-    '-moz-text-decoration-color': true,
-    '-moz-text-decoration-style': true,
-    '-moz-text-decoration-line': true
+    'text-decoration-color': true,
+    'text-decoration-style': true,
+    'text-decoration-line': true
   }
 };
 
diff --git a/chat/modules/test/test_filtering.js b/chat/modules/test/test_filtering.js
index 897f311570..82206cd375 100644
--- a/chat/modules/test/test_filtering.js
+++ b/chat/modules/test/test_filtering.js
@@ -148,8 +148,8 @@ function test_standardMode() {
     let string = "<span style=\"" + css + "\">foo</span>";
     do_check_eq(string, cleanupImMarkup(string));
   }
-  // text-decoration is a shorthand for several -moz-text-decoration properties.
-  do_check_eq("<span style=\"-moz-text-decoration-line: underline;\">foo</span>",
+  // text-decoration is a shorthand for several text-decoration properties.
+  do_check_eq("<span style=\"text-decoration-line: underline;\">foo</span>",
               cleanupImMarkup("<span style=\"text-decoration: underline\">foo</span>"));
 
   const badCSS = [