diff --git a/src/modules/Workspaces/WorkspacesLauncher/main.cpp b/src/modules/Workspaces/WorkspacesLauncher/main.cpp
index 38e88acd48..9f3d151097 100644
--- a/src/modules/Workspaces/WorkspacesLauncher/main.cpp
+++ b/src/modules/Workspaces/WorkspacesLauncher/main.cpp
@@ -16,6 +16,7 @@
 
 const std::wstring moduleName = L"Workspaces\\WorkspacesLauncher";
 const std::wstring internalPath = L"";
+const std::wstring instanceMutexName = L"Local\\PowerToys_WorkspacesLauncher_InstanceMutex";
 
 int APIENTRY WinMain(HINSTANCE hInst, HINSTANCE hInstPrev, LPSTR cmdline, int cmdShow)
 {
@@ -28,6 +29,18 @@ int APIENTRY WinMain(HINSTANCE hInst, HINSTANCE hInstPrev, LPSTR cmdline, int cm
         return 0;
     }
 
+    auto mutex = CreateMutex(nullptr, true, instanceMutexName.c_str());
+    if (mutex == nullptr)
+    {
+        Logger::error(L"Failed to create mutex. {}", get_last_error_or_default(GetLastError()));
+    }
+
+    if (GetLastError() == ERROR_ALREADY_EXISTS)
+    {
+        Logger::warn(L"WorkspacesLauncher instance is already running");
+        return 0;
+    }
+
     std::wstring cmdLineStr{ GetCommandLineW() };
     auto cmdArgs = split(cmdLineStr, L" ");
     if (cmdArgs.workspaceId.empty())