diff --git a/host/platform/Windows/capture/DXGI/src/com_ref.c b/host/platform/Windows/capture/DXGI/src/com_ref.c
index 9b42f0b1..3aa1c010 100644
--- a/host/platform/Windows/capture/DXGI/src/com_ref.c
+++ b/host/platform/Windows/capture/DXGI/src/com_ref.c
@@ -32,12 +32,16 @@ typedef struct
 }
 COMRef;
 
+static bool   comInit          = false;
 static int    comScope         = -1;
 static Vector comObjectsLocal  = {0};
 static Vector comObjectsGlobal = {0};
 
 bool comRef_init(unsigned globals, unsigned locals)
 {
+  if (comInit)
+    return true;
+
   if (!vector_create(&comObjectsGlobal, sizeof(COMRef), globals))
     return false;
 
@@ -47,11 +51,15 @@ bool comRef_init(unsigned globals, unsigned locals)
     return false;
   }
 
+  comInit = true;
   return true;
 }
 
 void comRef_free(void)
 {
+  if (!comInit)
+    return;
+
   COMRef * ref;
 
   if (comScope > -1)
@@ -74,10 +82,13 @@ void comRef_free(void)
   comScope = -1;
   vector_destroy(&comObjectsLocal);
   vector_destroy(&comObjectsGlobal);
+  comInit = false;
 }
 
 static IUnknown ** comRef_new(Vector * vector, IUnknown *** dst)
 {
+  DEBUG_ASSERT(comInit && "comRef has not been initialized");
+
   // we must not allow the vector to grow as if the realloc moves to a new
   // address it will invalidate any external pointers to members in it
   DEBUG_ASSERT(vector_size(vector) < vector_capacity(vector) &&
@@ -112,10 +123,15 @@ IUnknown ** comRef_newLocal(IUnknown *** dst)
   return ret;
 }
 
-void comRef_scopePush(void) { ++comScope; }
+void comRef_scopePush(void)
+{
+  DEBUG_ASSERT(comInit && "comRef has not been initialized");
+  ++comScope;
+}
 
 void comRef_scopePop(void)
 {
+  DEBUG_ASSERT(comInit && "comRef has not been initialized");
   DEBUG_ASSERT(comScope >= 0);
 
   COMRef * ref;
diff --git a/host/platform/Windows/capture/DXGI/src/com_ref.h b/host/platform/Windows/capture/DXGI/src/com_ref.h
index 2134180b..99ff7fb1 100644
--- a/host/platform/Windows/capture/DXGI/src/com_ref.h
+++ b/host/platform/Windows/capture/DXGI/src/com_ref.h
@@ -58,6 +58,9 @@ IUnknown ** comRef_newLocal(IUnknown *** dst);
  */
 inline static ULONG comRef_release(IUnknown ** ref)
 {
+  if (!ref)
+    return 0;
+
   ULONG count = 0;
   if (*ref)
     count = IUnknown_Release(*ref);