diff --git a/src/desktop/main.ts b/src/desktop/main.ts
index 8f384e722d..285a91447d 100644
--- a/src/desktop/main.ts
+++ b/src/desktop/main.ts
@@ -883,6 +883,9 @@ function createWindow() {
       nodeIntegration: false,
       contextIsolation: true,
       preload: path.join(__dirname, "../preload.js"),
+      // Disable the native spellchecker: mux is a coding tool where inputs are
+      // full of code, paths, and identifiers that trigger noisy red squiggles.
+      spellcheck: false,
     },
     title: "mux - coder multiplexer",
     // Hide menu bar on Linux by default (like VS Code)
diff --git a/src/desktop/terminalWindowManager.ts b/src/desktop/terminalWindowManager.ts
index 4a6e1987fc..61b4116ac6 100644
--- a/src/desktop/terminalWindowManager.ts
+++ b/src/desktop/terminalWindowManager.ts
@@ -55,6 +55,8 @@ export class TerminalWindowManager {
         contextIsolation: true,
         // __dirname is dist/services/ but preload.js is in dist/
         preload: path.join(__dirname, "../preload.js"),
+        // Disable spellcheck to match the main window; terminal content is code.
+        spellcheck: false,
       },
       backgroundColor: "#1e1e1e",
     });