diff --git a/dlls/dmsynth/synth.c b/dlls/dmsynth/synth.c
index 5453c296be3..ecf1dead8a8 100644
--- a/dlls/dmsynth/synth.c
+++ b/dlls/dmsynth/synth.c
@@ -1992,7 +1992,7 @@ HRESULT synth_create(IUnknown **ret_iface)
         goto failed;
     fluid_sfont_set_data(obj->fluid_sfont, obj);
 
-    InitializeCriticalSection(&obj->cs);
+    InitializeCriticalSectionEx(&obj->cs, 0, RTL_CRITICAL_SECTION_FLAG_FORCE_DEBUG_INFO);
     obj->cs.DebugInfo->Spare[0] = (DWORD_PTR)(__FILE__ ": cs");
 
     TRACE("Created DirectMusicSynth %p\n", obj);
diff --git a/dlls/dmsynth/synthsink.c b/dlls/dmsynth/synthsink.c
index 9263ff56349..c0ac7871f9a 100644
--- a/dlls/dmsynth/synthsink.c
+++ b/dlls/dmsynth/synthsink.c
@@ -754,7 +754,7 @@ HRESULT synth_sink_create(IUnknown **ret_iface)
     obj->ref = 1;
 
     obj->stop_event = CreateEventW(NULL, FALSE, FALSE, NULL);
-    InitializeCriticalSection(&obj->cs);
+    InitializeCriticalSectionEx(&obj->cs, 0, RTL_CRITICAL_SECTION_FLAG_FORCE_DEBUG_INFO);
     obj->cs.DebugInfo->Spare[0] = (DWORD_PTR)(__FILE__ ": cs");
 
     TRACE("Created DirectMusicSynthSink %p\n", obj);