diff --git a/browser/themes/linux/jar.mn b/browser/themes/linux/jar.mn
index 1e7b4536f9ec..ee3118e77da4 100644
--- a/browser/themes/linux/jar.mn
+++ b/browser/themes/linux/jar.mn
@@ -493,8 +493,7 @@ browser.jar:
 #ifdef E10S_TESTING_ONLY
   skin/classic/browser/e10s-64@2x.png (../shared/e10s-64@2x.png)
 #endif
-  skin/classic/browser/warning16.png                        (../shared/warning16.png)
-  skin/classic/browser/warning16@2x.png                     (../shared/warning16@2x.png)
+  skin/classic/browser/warning.svg                        (../shared/warning.svg)
 
 ../extensions/{972ce4c6-7e08-4474-a285-3208198ce6fd}/chrome.jar:
 % override chrome://browser/skin/feeds/audioFeedIcon.png              chrome://browser/skin/feeds/feedIcon.png
diff --git a/browser/themes/osx/jar.mn b/browser/themes/osx/jar.mn
index 0a829d592d24..d4686b72dc13 100644
--- a/browser/themes/osx/jar.mn
+++ b/browser/themes/osx/jar.mn
@@ -623,8 +623,7 @@ browser.jar:
 #ifdef E10S_TESTING_ONLY
   skin/classic/browser/e10s-64@2x.png (../shared/e10s-64@2x.png)
 #endif
-  skin/classic/browser/warning16.png                        (../shared/warning16.png)
-  skin/classic/browser/warning16@2x.png                     (../shared/warning16@2x.png)
+  skin/classic/browser/warning.svg                        (../shared/warning.svg)
 
 ../extensions/{972ce4c6-7e08-4474-a285-3208198ce6fd}/chrome.jar:
 % override chrome://browser/skin/feeds/audioFeedIcon.png                   chrome://browser/skin/feeds/feedIcon.png
diff --git a/browser/themes/shared/customizableui/panelUIOverlay.inc.css b/browser/themes/shared/customizableui/panelUIOverlay.inc.css
index e621d0f6fd70..646f3baf5aab 100644
--- a/browser/themes/shared/customizableui/panelUIOverlay.inc.css
+++ b/browser/themes/shared/customizableui/panelUIOverlay.inc.css
@@ -642,8 +642,8 @@ toolbarpaletteitem[place="palette"] > toolbaritem > toolbarbutton {
 
 #PanelUI-footer-fxa[fxastatus="migrate-signup"] > #PanelUI-fxa-status > #PanelUI-fxa-label,
 #PanelUI-footer-fxa[fxastatus="migrate-verify"] > #PanelUI-fxa-status > #PanelUI-fxa-label {
-  list-style-image: url(chrome://browser/skin/warning16.png);
-  -moz-image-region: rect(0, 32px, 16px, 16px);
+  list-style-image: url(chrome://browser/skin/warning.svg);
+  -moz-image-region: auto;
 }
 
 #PanelUI-customize {
@@ -1509,12 +1509,6 @@ menuitem[checked="true"].subviewbutton > .menu-iconic-left {
     list-style-image: url(chrome://browser/skin/syncProgress-horizontalbar@2x.png);
   }
 
-  #PanelUI-footer-fxa[fxastatus="migrate-signup"] > #PanelUI-fxa-status > #PanelUI-fxa-label,
-  #PanelUI-footer-fxa[fxastatus="migrate-verify"] > #PanelUI-fxa-status > #PanelUI-fxa-label {
-    list-style-image: url(chrome://browser/skin/warning16@2x.png);
-    -moz-image-region: rect(0, 64px, 32px, 32px);
-  }
-
   #PanelUI-customize {
     list-style-image: url(chrome://browser/skin/menuPanel-customize@2x.png);
   }
diff --git a/browser/themes/shared/warning.svg b/browser/themes/shared/warning.svg
new file mode 100644
index 000000000000..7befd73d9f65
--- /dev/null
+++ b/browser/themes/shared/warning.svg
@@ -0,0 +1,7 @@
+<!-- This Source Code Form is subject to the terms of the Mozilla Public
+   - License, v. 2.0. If a copy of the MPL was not distributed with this
+   - file, You can obtain one at http://mozilla.org/MPL/2.0/. -->
+<svg xmlns="http://www.w3.org/2000/svg" width="16" height="16" viewBox="0 0 16 16">
+  <path fill="#ffbf00" d="M14.8,12.5L9.3,1.9C9,1.3,8.5,1,8,1C7.5,1,7,1.3,6.7,1.9L1.2,12.5c-0.3,0.6-0.3,1.2,0,1.7C1.5,14.7,2,15,2.6,15h10.8 c0.6,0,1.1-0.3,1.4-0.8C15.1,13.7,15.1,13.1,14.8,12.5z"/>
+  <path fill="#fff" d="M8,11c-0.8,0-1.5,0.7-1.5,1.5C6.5,13.3,7.2,14,8,14 c0.8,0,1.5-0.7,1.5-1.5C9.5,11.7,8.8,11,8,11z M8,10L8,10C8.6,10,9,9.6,9,9l0.2-4.2c0-0.7-0.5-1.2-1.2-1.2S6.8,4.1,6.8,4.8L7,9 C7,9.6,7.4,10,8,10z"/>
+</svg>
diff --git a/browser/themes/shared/warning16.png b/browser/themes/shared/warning16.png
deleted file mode 100644
index 46200cec5cf0..000000000000
Binary files a/browser/themes/shared/warning16.png and /dev/null differ
diff --git a/browser/themes/shared/warning16@2x.png b/browser/themes/shared/warning16@2x.png
deleted file mode 100644
index d1426d381a33..000000000000
Binary files a/browser/themes/shared/warning16@2x.png and /dev/null differ
diff --git a/browser/themes/windows/jar.mn b/browser/themes/windows/jar.mn
index dbe9d82b6637..60189c3cb86b 100644
--- a/browser/themes/windows/jar.mn
+++ b/browser/themes/windows/jar.mn
@@ -598,8 +598,7 @@ browser.jar:
 #ifdef E10S_TESTING_ONLY
         skin/classic/browser/e10s-64@2x.png (../shared/e10s-64@2x.png)
 #endif
-        skin/classic/browser/warning16.png                            (../shared/warning16.png)
-        skin/classic/browser/warning16@2x.png                         (../shared/warning16@2x.png)
+        skin/classic/browser/warning.svg                            (../shared/warning.svg)
 
 ../extensions/{972ce4c6-7e08-4474-a285-3208198ce6fd}/chrome.jar:
 % override chrome://browser/skin/page-livemarks.png                   chrome://browser/skin/feeds/feedIcon16.png