diff --git a/Makefile b/Makefile
index 2fa1153..cceade9 100644
--- a/Makefile
+++ b/Makefile
@@ -53,7 +53,9 @@ install: bundle
 	@rm -rf /Applications/$(APP_NAME).app
 	@cp -R $(APP_BUNDLE) /Applications/$(APP_NAME).app
 	@xattr -cr /Applications/$(APP_NAME).app
-	@echo "Installed /Applications/$(APP_NAME).app"
+	@mkdir -p "$(HOME)/Library/Application Support/Pommedoro"
+	@echo "dev" > "$(HOME)/Library/Application Support/Pommedoro/current.sha256"
+	@echo "Installed /Applications/$(APP_NAME).app (dev build – auto-update disabled)"
 
 run: bundle
 	@open $(APP_BUNDLE)
diff --git a/Sources/Pommedoro/AutoUpdater.swift b/Sources/Pommedoro/AutoUpdater.swift
index cb787ec..c40ccda 100644
--- a/Sources/Pommedoro/AutoUpdater.swift
+++ b/Sources/Pommedoro/AutoUpdater.swift
@@ -9,6 +9,10 @@ enum AutoUpdater {
 
     // MARK: - Configuration
 
+    /// Sentinel value written by `make install` to indicate a dev build.
+    /// The updater skips automatic updates when this is the local stamp.
+    private static let devSentinel = "dev"
+
     /// Raw URL for the SHA256 file in the repo (Gitea raw endpoint)
     private static let remoteSHA256URL = URL(
         string: "https://git.nixc.us/colin/pommedoro/raw/branch/main/releases/Pommedoro.dmg.sha256"
@@ -49,48 +53,56 @@ enum AutoUpdater {
     // MARK: - Core Logic
 
     private static func performCheck(silent: Bool) {
-        // 1. Fetch remote SHA256
+        // 1. Read local SHA256 (written at last install/build)
+        let localSHA = readLocalSHA()
+
+        // 2. Dev builds are stamped "dev" – skip silent checks entirely
+        if localSHA == devSentinel {
+            if !silent {
+                showAlert(title: "Dev Build", message: "Auto-update is disabled for local dev builds.")
+            }
+            return
+        }
+
+        // 3. Fetch remote SHA256
         guard let remoteSHA = fetchRemoteSHA() else {
             if !silent { showAlert(title: "Update Check Failed", message: "Could not reach the update server.") }
             return
         }
 
-        // 2. Read local SHA256 (written at last install/build)
-        let localSHA = readLocalSHA()
-
-        // 3. Compare
+        // 4. Compare
         if remoteSHA == localSHA {
             if !silent { showAlert(title: "Up to Date", message: "You are running the latest version.") }
             return
         }
 
-        // 4. There's an update – prompt user
+        // 5. There's an update – prompt user
         let shouldUpdate = promptForUpdate()
         guard shouldUpdate else { return }
 
-        // 5. Download new DMG
+        // 6. Download new DMG
         guard downloadDMG() else {
             showAlert(title: "Update Failed", message: "Could not download the update.")
             return
         }
 
-        // 6. Verify downloaded DMG matches remote SHA
+        // 7. Verify downloaded DMG matches remote SHA
         guard let downloadedSHA = sha256(of: downloadedDMGPath), downloadedSHA == remoteSHA else {
             showAlert(title: "Update Failed", message: "Downloaded file integrity check failed.")
             try? FileManager.default.removeItem(at: downloadedDMGPath)
             return
         }
 
-        // 7. Extract new app from DMG to staging area
+        // 8. Extract new app from DMG to staging area
         guard stageFromDMG() else {
             showAlert(title: "Update Failed", message: "Could not extract the update.")
             return
         }
 
-        // 8. Save new SHA so we don't re-update next launch
+        // 9. Save new SHA so we don't re-update next launch
         try? remoteSHA.write(to: localSHAPath, atomically: true, encoding: .utf8)
 
-        // 9. Spawn swap script, then terminate so applicationWillTerminate saves state
+        // 10. Spawn swap script, then terminate so applicationWillTerminate saves state
         spawnSwapAndRelaunch()
 
         DispatchQueue.main.async {
@@ -142,7 +154,7 @@ enum AutoUpdater {
 
     // MARK: - SHA256 Computation
 
-    private static func sha256(of fileURL: URL) -> String? {
+    static func sha256(of fileURL: URL) -> String? {
         guard let handle = try? FileHandle(forReadingFrom: fileURL) else { return nil }
         defer { handle.closeFile() }
 
@@ -242,7 +254,6 @@ enum AutoUpdater {
         proc.arguments = [scriptPath]
         proc.standardOutput = FileHandle.nullDevice
         proc.standardError = FileHandle.nullDevice
-        // Detach from our process group so it survives our exit
         proc.qualityOfService = .utility
         try? proc.run()
     }
diff --git a/releases/Pommedoro.dmg b/releases/Pommedoro.dmg
index bfb63c8..e3df925 100644
Binary files a/releases/Pommedoro.dmg and b/releases/Pommedoro.dmg differ
diff --git a/releases/Pommedoro.dmg.sha256 b/releases/Pommedoro.dmg.sha256
index 8ac8a02..e9dc16b 100644
--- a/releases/Pommedoro.dmg.sha256
+++ b/releases/Pommedoro.dmg.sha256
@@ -1 +1 @@
-7e15ab9b42481c28c9566c7d71bad03558bb2cdec7dcceb956443caf5cb1724a
+98fa348545458a05d36e15656fdd788564e309784c4536a060499f0827141260