diff --git a/.github/workflows/nodejs.yml b/.github/workflows/nodejs.yml
index 40901325..ddf4bf18 100644
--- a/.github/workflows/nodejs.yml
+++ b/.github/workflows/nodejs.yml
@@ -14,7 +14,10 @@ jobs:
     strategy:
       matrix:
         node-version: [14.x]
-        os: [macos-11.0, ubuntu-latest, windows-latest]
+        os:
+          - macos-11.0
+          - ubuntu-18.04
+          - windows-latest
       fail-fast: false
     steps:
       - name: Checkout
diff --git a/lib/components/term.tsx b/lib/components/term.tsx
index b80f9d0f..54adb89a 100644
--- a/lib/components/term.tsx
+++ b/lib/components/term.tsx
@@ -176,7 +176,7 @@ export default class Term extends React.PureComponent<TermProps> {
       if (useWebGL) {
         this.term.loadAddon(new WebglAddon());
       }
-      if (props.disableLigatures !== true) {
+      if (props.disableLigatures !== true && !useWebGL) {
         this.term.loadAddon(new LigaturesAddon());
       }
       this.term.loadAddon(new Unicode11Addon());