diff --git a/browser/themes/linux/browser.css b/browser/themes/linux/browser.css
index 0a92f8a63de2..2b269e086c1a 100644
--- a/browser/themes/linux/browser.css
+++ b/browser/themes/linux/browser.css
@@ -1231,7 +1231,7 @@ toolbar[iconsize="small"] #webrtc-status-button {
   border-radius: 2.5px 0 0 2.5px;
   border-width: 0 8px 0 0;
   border-style: solid;
-  -moz-border-image: url("chrome://browser/skin/urlbar-arrow.png") 0 8 0 0 fill;
+  border-image: url("chrome://browser/skin/urlbar-arrow.png") 0 8 0 0 fill;
   -moz-margin-end: -8px;
   margin-top: -1px;
   margin-bottom: -1px;
@@ -1587,7 +1587,7 @@ richlistitem[type~="action"][actiontype="switchtab"] > .ac-url-box > .ac-action-
   padding: 0;
   border-width: 4px 5px 3px 6px;
   border-style: solid;
-  -moz-border-image: url(tabbrowser/tab.png) 4 5 3 6 fill repeat stretch;
+  border-image: url(tabbrowser/tab.png) 4 5 3 6 fill repeat stretch;
   border-radius: 10px 8px 0 0;
   min-height: 25px; /* reserve space for the sometimes hidden close button */
 }
@@ -1761,14 +1761,14 @@ richlistitem[type~="action"][actiontype="switchtab"] > .ac-url-box > .ac-action-
 .tabbrowser-arrowscrollbox > .scrollbutton-down:not([disabled]):-moz-locale-dir(rtl) {
   border-width: 0 2px 0 0;
   border-style: solid;
-  -moz-border-image: url("chrome://browser/skin/tabbrowser/tab-overflow-border.png") 0 2 0 2 fill;
+  border-image: url("chrome://browser/skin/tabbrowser/tab-overflow-border.png") 0 2 0 2 fill;
 }
 
 .tabbrowser-arrowscrollbox > .scrollbutton-down:not([disabled]):-moz-locale-dir(ltr),
 .tabbrowser-arrowscrollbox > .scrollbutton-up:not([disabled]):-moz-locale-dir(rtl) {
   border-width: 0 0 0 2px;
   border-style: solid;
-  -moz-border-image: url("chrome://browser/skin/tabbrowser/tab-overflow-border.png") 0 2 0 2 fill;
+  border-image: url("chrome://browser/skin/tabbrowser/tab-overflow-border.png") 0 2 0 2 fill;
 }
 
 #TabsToolbar .toolbarbutton-1 > .toolbarbutton-icon,
diff --git a/browser/themes/osx/browser.css b/browser/themes/osx/browser.css
index 7ef0b48c2ffc..fbb0731d1edc 100644
--- a/browser/themes/osx/browser.css
+++ b/browser/themes/osx/browser.css
@@ -2326,46 +2326,46 @@ toolbarbutton.chevron > .toolbarbutton-menu-dropmarker {
 
 @TABSONTOP_TAB_STACK@ > .tab-content,
 @TABSONTOP_NEWTAB_BUTTON@ > .toolbarbutton-icon {
-  -moz-border-image: url(chrome://browser/skin/tabbrowser/tab-top-normal-active.png) 0 11 fill repeat stretch;
+  border-image: url(chrome://browser/skin/tabbrowser/tab-top-normal-active.png) 0 11 fill repeat stretch;
 }
 
 @TABSONTOP_TAB@:hover > .tab-stack > .tab-content:not([selected="true"]),
 @TABSONTOP_NEWTAB_BUTTON@:hover > .toolbarbutton-icon {
-  -moz-border-image: url(chrome://browser/skin/tabbrowser/tab-top-hover-active.png) 0 11 fill repeat stretch;
+  border-image: url(chrome://browser/skin/tabbrowser/tab-top-hover-active.png) 0 11 fill repeat stretch;
 }
 
 @TABSONTOP_TAB_STACK@ > .tab-content[selected="true"] {
-  -moz-border-image: url(chrome://browser/skin/tabbrowser/tab-top-selected-active.png) 0 11 fill repeat stretch;
+  border-image: url(chrome://browser/skin/tabbrowser/tab-top-selected-active.png) 0 11 fill repeat stretch;
 }
 
 @TABSONBOTTOM_TAB_STACK@ > .tab-content,
 @TABSONBOTTOM_NEWTAB_BUTTON@ > .toolbarbutton-icon {
-  -moz-border-image: url(chrome://browser/skin/tabbrowser/tab-bottom-normal-active.png) 0 11 fill repeat stretch;
+  border-image: url(chrome://browser/skin/tabbrowser/tab-bottom-normal-active.png) 0 11 fill repeat stretch;
 }
 
 @media (min-resolution: 2dppx) {
   @TABSONTOP_TAB_STACK@ > .tab-content,
   @TABSONTOP_NEWTAB_BUTTON@ > .toolbarbutton-icon {
-    -moz-border-image: url(chrome://browser/skin/tabbrowser/tab-top-normal-active@2x.png) 0 22 fill repeat stretch;
+    border-image: url(chrome://browser/skin/tabbrowser/tab-top-normal-active@2x.png) 0 22 fill repeat stretch;
   }
 
   @TABSONTOP_TAB@:hover > .tab-stack > .tab-content:not([selected="true"]),
   @TABSONTOP_NEWTAB_BUTTON@:hover > .toolbarbutton-icon {
-    -moz-border-image: url(chrome://browser/skin/tabbrowser/tab-top-hover-active@2x.png) 0 22 fill repeat stretch;
+    border-image: url(chrome://browser/skin/tabbrowser/tab-top-hover-active@2x.png) 0 22 fill repeat stretch;
   }
 
   @TABSONTOP_TAB_STACK@ > .tab-content[selected="true"] {
-    -moz-border-image: url(chrome://browser/skin/tabbrowser/tab-top-selected-active@2x.png) 0 22 fill repeat stretch;
+    border-image: url(chrome://browser/skin/tabbrowser/tab-top-selected-active@2x.png) 0 22 fill repeat stretch;
   }
 }
 
 @TABSONBOTTOM_TAB@:hover > .tab-stack > .tab-content:not([selected="true"]),
 @TABSONBOTTOM_NEWTAB_BUTTON@:hover > .toolbarbutton-icon {
-  -moz-border-image: url(chrome://browser/skin/tabbrowser/tab-bottom-hover-active.png) 0 11 fill repeat stretch;
+  border-image: url(chrome://browser/skin/tabbrowser/tab-bottom-hover-active.png) 0 11 fill repeat stretch;
 }
 
 @TABSONBOTTOM_TAB_STACK@ > .tab-content[selected="true"] {
-  -moz-border-image: url(chrome://browser/skin/tabbrowser/tab-bottom-selected-active.png) 0 11 fill repeat stretch;
+  border-image: url(chrome://browser/skin/tabbrowser/tab-bottom-selected-active.png) 0 11 fill repeat stretch;
 }
 
 /* preloading hack */
@@ -2659,14 +2659,14 @@ toolbarbutton.chevron > .toolbarbutton-menu-dropmarker {
 .tabbrowser-arrowscrollbox > .scrollbutton-down:not([disabled]):-moz-locale-dir(rtl) {
   border-width: 0 2px 0 0;
   border-style: solid;
-  -moz-border-image: url("chrome://browser/skin/tabbrowser/tab-overflow-border.png") 0 2 0 2 fill;
+  border-image: url("chrome://browser/skin/tabbrowser/tab-overflow-border.png") 0 2 0 2 fill;
 }
 
 .tabbrowser-arrowscrollbox > .scrollbutton-down:not([disabled]):-moz-locale-dir(ltr),
 .tabbrowser-arrowscrollbox > .scrollbutton-up:not([disabled]):-moz-locale-dir(rtl) {
   border-width: 0 0 0 2px;
   border-style: solid;
-  -moz-border-image: url("chrome://browser/skin/tabbrowser/tab-overflow-border.png") 0 2 0 2 fill;
+  border-image: url("chrome://browser/skin/tabbrowser/tab-overflow-border.png") 0 2 0 2 fill;
 }
 
 /**
@@ -2979,13 +2979,13 @@ toolbarbutton.chevron > .toolbarbutton-menu-dropmarker {
   border-radius: 2px 0 0 2px;
   border-width: 0 8px 0 0;
   border-style: solid;
-  -moz-border-image: url("chrome://browser/skin/urlbar-arrow.png") 0 8 0 0 fill;
+  border-image: url("chrome://browser/skin/urlbar-arrow.png") 0 8 0 0 fill;
   -moz-margin-end: -8px;
 }
 
 @media (min-resolution: 2dppx) {
   #notification-popup-box {
-    -moz-border-image: url("chrome://browser/skin/urlbar-arrow@2x.png") 0 16 0 0 fill;
+    border-image: url("chrome://browser/skin/urlbar-arrow@2x.png") 0 16 0 0 fill;
   }
 }
 
diff --git a/browser/themes/windows/browser.css b/browser/themes/windows/browser.css
index 4385c984cc03..4f8c1eb58e09 100644
--- a/browser/themes/windows/browser.css
+++ b/browser/themes/windows/browser.css
@@ -1804,7 +1804,7 @@ richlistitem[type~="action"][actiontype="switchtab"] > .ac-url-box > .ac-action-
   padding: 2px 0 4px;
   border-width: 4px 3px 0;
   border-style: solid;
-  -moz-border-image: url(tabbrowser/tab.png) 4 3 0 fill repeat stretch;
+  border-image: url(tabbrowser/tab.png) 4 3 0 fill repeat stretch;
   border-radius: 0;
 }
 
@@ -1977,7 +1977,7 @@ richlistitem[type~="action"][actiontype="switchtab"] > .ac-url-box > .ac-action-
 .tabbrowser-arrowscrollbox > .scrollbutton-down:not([disabled]) {
   border-width: 0 2px 0 0;
   border-style: solid;
-  -moz-border-image: url("chrome://browser/skin/tabbrowser/tab-overflow-border.png") 0 2 0 2 fill;
+  border-image: url("chrome://browser/skin/tabbrowser/tab-overflow-border.png") 0 2 0 2 fill;
 }
 
 .tabs-newtab-button > .toolbarbutton-icon {
@@ -2288,7 +2288,7 @@ toolbarbutton.bookmark-item[dragover="true"][open="true"] {
   border-radius: 2.5px 0 0 2.5px;
   border-width: 0 8px 0 0;
   border-style: solid;
-  -moz-border-image: url("chrome://browser/skin/urlbar-arrow.png") 0 8 0 0 fill;
+  border-image: url("chrome://browser/skin/urlbar-arrow.png") 0 8 0 0 fill;
   -moz-margin-end: -8px;
 }