diff --git a/Cargo.lock b/Cargo.lock
index 31d65df..95898c0 100644
--- a/Cargo.lock
+++ b/Cargo.lock
@@ -452,7 +452,7 @@ checksum = "69cdb34c158ceb288df11e18b4bd39de994f6657d83847bdffdbd7f346754b0f"
 
 [[package]]
 name = "ranma-cli"
-version = "0.1.10"
+version = "0.1.11"
 dependencies = [
  "argh",
  "libc",
@@ -462,7 +462,7 @@ dependencies = [
 
 [[package]]
 name = "ranma-core"
-version = "0.1.10"
+version = "0.1.11"
 dependencies = [
  "parking_lot",
  "serde",
@@ -737,7 +737,7 @@ dependencies = [
 
 [[package]]
 name = "uniffi-bindgen"
-version = "0.1.10"
+version = "0.1.11"
 dependencies = [
  "uniffi",
 ]
diff --git a/app/Sources/BarViewModel.swift b/app/Sources/BarViewModel.swift
index 0932b4f..717ba68 100644
--- a/app/Sources/BarViewModel.swift
+++ b/app/Sources/BarViewModel.swift
@@ -207,7 +207,7 @@ final class BarViewModel: StateChangeHandler, @unchecked Sendable {
         for screen in NSScreen.screens {
             let displayID = screen.displayID
             let uuid = CGDisplayCreateUUIDFromDisplayID(displayID).takeRetainedValue()
-            let uuidString = CFUUIDCreateString(nil, uuid) as CFString
+            guard let uuidString = CFUUIDCreateString(nil, uuid) else { continue }
 
             let spaceID = SLSManagedDisplayGetCurrentSpace(cid, uuidString)
             if spaceID != 0 && SLSSpaceGetType(cid, spaceID) == 4 {