diff --git a/src/zen/boosts/ZenBoostsEditor.mjs b/src/zen/boosts/ZenBoostsEditor.mjs
index 7254ac3fd..2b224690c 100644
--- a/src/zen/boosts/ZenBoostsEditor.mjs
+++ b/src/zen/boosts/ZenBoostsEditor.mjs
@@ -638,7 +638,7 @@ ${cssSelector} {
   /**
    * Handles the size toggle button press, cycling through size override options
    */
-  onBoostSizePressed() {
+  async onBoostSizePressed() {
     if (this.currentBoostData.sizeOverride == 1) {
       this.currentBoostData.sizeOverride = 1.1;
     } else if (this.currentBoostData.sizeOverride == 1.1) {
@@ -649,6 +649,12 @@ ${cssSelector} {
       this.currentBoostData.sizeOverride = 0.9;
     } else if (this.currentBoostData.sizeOverride == 0.9) {
       this.currentBoostData.sizeOverride = 1;
+
+      const linkedBrowser =
+        this.openerWindow.gBrowser.selectedTab.linkedBrowser;
+      const actor =
+        linkedBrowser.browsingContext.currentWindowGlobal.getActor("ZenBoosts");
+      await actor.sendQuery("ZenBoost:DisableSizeOverride");
     }
 
     this.updateSizeButtonVisuals();
diff --git a/src/zen/boosts/actors/ZenBoostsChild.sys.mjs b/src/zen/boosts/actors/ZenBoostsChild.sys.mjs
index 597a74c09..13551682f 100644
--- a/src/zen/boosts/actors/ZenBoostsChild.sys.mjs
+++ b/src/zen/boosts/actors/ZenBoostsChild.sys.mjs
@@ -280,6 +280,9 @@ export class ZenBoostsChild extends JSWindowActorChild {
       case "ZenBoost:OpenInspector":
         this.sendAsyncMessage("ZenBoost:OpenInspector");
         break;
+      case "ZenBoost:DisableSizeOverride":
+        this.disableSizeOverride();
+        break;
     }
     return null;
   }
@@ -549,6 +552,14 @@ export class ZenBoostsChild extends JSWindowActorChild {
     this.sendNotify("selector-picker-state-update", "ondisable");
   }
 
+  disableSizeOverride() {
+    const browsingContext = this.browsingContext;
+    if (!browsingContext || browsingContext.parent !== null) {
+      return;
+    }
+    browsingContext.fullZoom = 1;
+  }
+
   sendNotify(topic, msg = null) {
     this.sendAsyncMessage("ZenBoost:Notify", { topic, msg });
   }