diff --git a/dlls/itss/itss.c b/dlls/itss/itss.c
index b5379f56a69..de624464b3d 100644
--- a/dlls/itss/itss.c
+++ b/dlls/itss/itss.c
@@ -53,6 +53,8 @@ DEFINE_GUID(IID_IITStorage, 0x88cc31de, 0x27ab, 0x11d0, 0x9d, 0xf9, 0x0, 0xa0, 0
 
 static HRESULT ITSS_create(IUnknown *pUnkOuter, LPVOID *ppObj);
 
+ULONG dll_count = 0;
+
 BOOL WINAPI DllMain(HINSTANCE hInstDLL, DWORD fdwReason, LPVOID lpv)
 {
     switch(fdwReason) {
@@ -117,8 +119,10 @@ static ULONG WINAPI ITSSCF_Release(LPCLASSFACTORY iface)
 
     ULONG ref = InterlockedDecrement(&This->ref);
 
-    if (ref == 0)
-	HeapFree(GetProcessHeap(), 0, This);
+    if (ref == 0) {
+        HeapFree(GetProcessHeap(), 0, This);
+        InterlockedDecrement(&dll_count);
+    }
 
     return ref;
 }
@@ -193,6 +197,7 @@ HRESULT WINAPI ITSS_DllGetClassObject(REFCLSID rclsid, REFIID iid, LPVOID *ppv)
     factory->pfnCreateInstance = object_creation[i].pfnCreateInstance;
 
     *ppv = &(factory->ITF_IClassFactory);
+    InterlockedIncrement(&dll_count);
 
     TRACE("(%p) <- %p\n", ppv, &(factory->ITF_IClassFactory) );
 
@@ -239,8 +244,10 @@ ULONG WINAPI ITStorageImpl_Release(
     ITStorageImpl *This = (ITStorageImpl *)iface;
     ULONG ref = InterlockedDecrement(&This->ref);
 
-    if (ref == 0)
-	HeapFree(GetProcessHeap(), 0, This);
+    if (ref == 0) {
+        HeapFree(GetProcessHeap(), 0, This);
+        InterlockedDecrement(&dll_count);
+    }
 
     return ref;
 }
@@ -393,6 +400,7 @@ static HRESULT ITSS_create(IUnknown *pUnkOuter, LPVOID *ppObj)
 
     TRACE("-> %p\n", its);
     *ppObj = (LPVOID) its;
+    InterlockedIncrement(&dll_count);
 
     return S_OK;
 }
@@ -405,9 +413,8 @@ HRESULT WINAPI ITSS_DllRegisterServer(void)
     return S_OK;
 }
 
-BOOL WINAPI ITSS_DllCanUnloadNow(void)
+HRESULT WINAPI ITSS_DllCanUnloadNow(void)
 {
-    FIXME("\n");
-
-    return FALSE;
+    TRACE("dll_count = %lu\n", dll_count);
+    return dll_count ? S_FALSE : S_OK;
 }
diff --git a/dlls/itss/moniker.c b/dlls/itss/moniker.c
index 588a1bd750e..e62318e05f8 100644
--- a/dlls/itss/moniker.c
+++ b/dlls/itss/moniker.c
@@ -44,6 +44,8 @@
 
 WINE_DEFAULT_DEBUG_CHANNEL(itss);
 
+extern ULONG dll_count;
+
 /*****************************************************************************/
 
 typedef struct {
@@ -78,17 +80,19 @@ static ULONG WINAPI ITS_IMonikerImpl_AddRef(
 {
     ITS_IMonikerImpl *This = (ITS_IMonikerImpl *)iface;
     TRACE("%p\n", This);
-    return ++(This->ref);
+    return InterlockedIncrement(&This->ref);
 }
 
 static ULONG WINAPI ITS_IMonikerImpl_Release(
     IMoniker* iface)
 {
     ITS_IMonikerImpl *This = (ITS_IMonikerImpl *)iface;
-    ULONG ref = --This->ref;
+    ULONG ref = InterlockedDecrement(&This->ref);
 
-    if (ref == 0)
-	HeapFree(GetProcessHeap(), 0, This);
+    if (ref == 0) {
+        HeapFree(GetProcessHeap(), 0, This);
+        InterlockedDecrement(&dll_count);
+    }
 
     return ref;
 }
@@ -365,6 +369,7 @@ static HRESULT ITS_IMoniker_create( IMoniker **ppObj, LPWSTR name, DWORD n )
     TRACE("-> %p %s %s\n", itsmon,
           debugstr_w(itsmon->szFile), debugstr_w(itsmon->szHtml) );
     *ppObj = (IMoniker*) itsmon;
+    InterlockedIncrement(&dll_count);
 
     return S_OK;
 }
@@ -400,17 +405,19 @@ static ULONG WINAPI ITS_IParseDisplayNameImpl_AddRef(
 {
     ITS_IParseDisplayNameImpl *This = (ITS_IParseDisplayNameImpl *)iface;
     TRACE("%p\n", This);
-    return ++(This->ref);
+    return InterlockedIncrement(&This->ref);
 }
 
 static ULONG WINAPI ITS_IParseDisplayNameImpl_Release(
     IParseDisplayName* iface)
 {
     ITS_IParseDisplayNameImpl *This = (ITS_IParseDisplayNameImpl *)iface;
-    ULONG ref = --This->ref;
+    ULONG ref = InterlockedDecrement(&This->ref);
 
-    if (ref == 0)
-	HeapFree(GetProcessHeap(), 0, This);
+    if (ref == 0) {
+        HeapFree(GetProcessHeap(), 0, This);
+        InterlockedDecrement(&dll_count);
+    }
 
     return ref;
 }
@@ -470,6 +477,7 @@ HRESULT ITS_IParseDisplayName_create(IUnknown *pUnkOuter, LPVOID *ppObj)
 
     TRACE("-> %p\n", its);
     *ppObj = (LPVOID) its;
+    InterlockedIncrement(&dll_count);
 
     return S_OK;
 }
diff --git a/dlls/itss/storage.c b/dlls/itss/storage.c
index bc800a7f99c..221cc832bba 100644
--- a/dlls/itss/storage.c
+++ b/dlls/itss/storage.c
@@ -45,6 +45,8 @@
 
 WINE_DEFAULT_DEBUG_CHANNEL(itss);
 
+extern ULONG dll_count;
+
 /************************************************************************/
 
 typedef struct _ITSS_IStorageImpl
@@ -107,7 +109,7 @@ static ULONG WINAPI ITSS_IEnumSTATSTG_AddRef(
     IEnumSTATSTG* iface)
 {
     IEnumSTATSTG_Impl *This = (IEnumSTATSTG_Impl *)iface;
-    return ++(This->ref);
+    return InterlockedIncrement(&This->ref);
 }
 
 static ULONG WINAPI ITSS_IEnumSTATSTG_Release(
@@ -115,7 +117,7 @@ static ULONG WINAPI ITSS_IEnumSTATSTG_Release(
 {
     IEnumSTATSTG_Impl *This = (IEnumSTATSTG_Impl *)iface;
 
-    ULONG ref = --This->ref;
+    ULONG ref = InterlockedDecrement(&This->ref);
 
     if (ref == 0)
     {
@@ -125,7 +127,8 @@ static ULONG WINAPI ITSS_IEnumSTATSTG_Release(
             HeapFree( GetProcessHeap(), 0, This->first );
             This->first = t;
         }
-	HeapFree(GetProcessHeap(), 0, This);
+        HeapFree(GetProcessHeap(), 0, This);
+        InterlockedDecrement(&dll_count);
     }
 
     return ref;
@@ -251,6 +254,7 @@ static IEnumSTATSTG_Impl *ITSS_create_enum( void )
     stgenum->first = NULL;
     stgenum->last = NULL;
     stgenum->current = NULL;
+    InterlockedIncrement(&dll_count);
 
     TRACE(" -> %p\n", stgenum );
 
@@ -282,7 +286,7 @@ ULONG WINAPI ITSS_IStorageImpl_AddRef(
     IStorage* iface)
 {
     ITSS_IStorageImpl *This = (ITSS_IStorageImpl *)iface;
-    return ++(This->ref);
+    return InterlockedIncrement(&This->ref);
 }
 
 ULONG WINAPI ITSS_IStorageImpl_Release(
@@ -290,11 +294,12 @@ ULONG WINAPI ITSS_IStorageImpl_Release(
 {
     ITSS_IStorageImpl *This = (ITSS_IStorageImpl *)iface;
 
-    ULONG ref = --This->ref;
+    ULONG ref = InterlockedDecrement(&This->ref);
 
     if (ref == 0)
     {
-	HeapFree(GetProcessHeap(), 0, This);
+        HeapFree(GetProcessHeap(), 0, This);
+        InterlockedDecrement(&dll_count);
     }
 
     return ref;
@@ -569,6 +574,7 @@ static HRESULT ITSS_create_chm_storage(
     strcpyW( stg->dir, dir );
 
     *ppstgOpen = (IStorage*) stg;
+    InterlockedIncrement(&dll_count);
 
     return S_OK;
 }
@@ -619,7 +625,7 @@ static ULONG WINAPI ITSS_IStream_AddRef(
     IStream* iface)
 {
     IStream_Impl *This = (IStream_Impl *)iface;
-    return ++(This->ref);
+    return InterlockedIncrement(&This->ref);
 }
 
 static ULONG WINAPI ITSS_IStream_Release(
@@ -627,12 +633,13 @@ static ULONG WINAPI ITSS_IStream_Release(
 {
     IStream_Impl *This = (IStream_Impl *)iface;
 
-    ULONG ref = --This->ref;
+    ULONG ref = InterlockedDecrement(&This->ref);
 
     if (ref == 0)
     {
         IStorage_Release( (IStorage*) This->stg );
 	HeapFree(GetProcessHeap(), 0, This);
+        InterlockedDecrement(&dll_count);
     }
 
     return ref;
@@ -818,6 +825,7 @@ static IStream_Impl *ITSS_create_stream(
     memcpy( &stm->ui, ui, sizeof stm->ui );
     stm->stg = stg;
     IStorage_AddRef( (IStorage*) stg );
+    InterlockedIncrement(&dll_count);
 
     TRACE(" -> %p\n", stm );