diff --git a/source/plugin.cpp b/source/plugin.cpp
index 00e363c..ea304a2 100644
--- a/source/plugin.cpp
+++ b/source/plugin.cpp
@@ -136,7 +136,6 @@ MODULE_EXPORT void obs_module_unload(void)
 			_streamfx_gfx_opengl.reset();
 		}
 
-
 		DLOG_INFO("Unloaded Version %s", STREAMFX_VERSION_STRING);
 	} catch (std::exception const& ex) {
 		DLOG_ERROR("Unexpected exception in function '%s': %s", __FUNCTION_NAME__, ex.what());
diff --git a/source/windll.cpp b/source/windll.cpp
index 14fefe7..0d561d4 100644
--- a/source/windll.cpp
+++ b/source/windll.cpp
@@ -4,9 +4,25 @@
 
 #include "warning-disable.hpp"
 #include <Windows.h>
+#include <mutex>
 #include "warning-enable.hpp"
 
-BOOL WINAPI DllMain(HINSTANCE, DWORD, LPVOID)
+std::shared_ptr<void> local_mutex;
+std::shared_ptr<void> global_mutex;
+
+BOOL WINAPI DllMain(HINSTANCE, DWORD dwReason, LPVOID)
 {
+	if (dwReason == DLL_PROCESS_ATTACH) {
+		// Prevent installer from progressing while StreamFX is still active.
+		local_mutex  = std::shared_ptr<void>(CreateMutexW(NULL, TRUE, L"Local\\StreamFX-Setup"), [](HANDLE p) {
+            ReleaseMutex(p);
+            CloseHandle(p);
+        });
+		global_mutex = std::shared_ptr<void>(CreateMutexW(NULL, TRUE, L"Global\\StreamFX-Setup"), [](HANDLE p) {
+			ReleaseMutex(p);
+			CloseHandle(p);
+		});
+	}
+
 	return TRUE;
 }