diff --git a/packages/plugin-ext/src/main/browser/style/webview.css b/packages/plugin-ext/src/main/browser/style/webview.css
index 64e9d04673179..4484abee04005 100644
--- a/packages/plugin-ext/src/main/browser/style/webview.css
+++ b/packages/plugin-ext/src/main/browser/style/webview.css
@@ -29,3 +29,20 @@
     background: none !important;
     min-height: 20px;
 }
+
+.webview-icon::before {
+    background-size: 13px;
+    background-repeat: no-repeat;
+    vertical-align: middle;
+    display: inline-block;
+    text-align: center;
+    height: 15px;
+    width: 15px;
+    content: "";
+}
+
+.p-TabBar.theia-app-sides .webview-icon::before {
+    width: var(--theia-private-sidebar-icon-size);
+    height: var(--theia-private-sidebar-icon-size);
+    background-size: contain;
+}
diff --git a/packages/plugin-ext/src/main/browser/webview/theme-rules-service.ts b/packages/plugin-ext/src/main/browser/webview/theme-rules-service.ts
index fbc4849a8eccc..ae8dff515e2c5 100644
--- a/packages/plugin-ext/src/main/browser/webview/theme-rules-service.ts
+++ b/packages/plugin-ext/src/main/browser/webview/theme-rules-service.ts
@@ -120,15 +120,7 @@ export class ThemeRulesService {
         if (!this.styleElement) {
             return;
         }
-        const cssRules: string[] = [`.webview-icon::before {
-            background-repeat: no-repeat;
-            vertical-align: middle;
-            display: inline-block;
-            text-align: center;
-            height: 11px;
-            width: 11px;
-            content: "";
-        }`];
+        const cssRules: string[] = [];
         this.icons.forEach((value, key) => {
             let path: string;
             if (typeof value === 'string') {