diff --git a/reactos/dll/win32/kernel32/client/synch.c b/reactos/dll/win32/kernel32/client/synch.c
index 3d577fe2e2e..dede163c9a0 100644
--- a/reactos/dll/win32/kernel32/client/synch.c
+++ b/reactos/dll/win32/kernel32/client/synch.c
@@ -702,6 +702,9 @@ SleepEx(IN DWORD dwMilliseconds,
         errCode = NtDelayExecution((BOOLEAN)bAlertable, TimePtr);
     }
     while ((bAlertable) && (errCode == STATUS_ALERTED));
+    
+    /* Cleanup the activation context */
+    if (bAlertable) RtlDeactivateActivationContextUnsafeFast(&ActCtx);
 
     /* Return the correct code */
     return (errCode == STATUS_USER_APC) ? WAIT_IO_COMPLETION : 0;
diff --git a/reactos/lib/rtl/actctx.c b/reactos/lib/rtl/actctx.c
index 7984cf1e802..e607960033f 100644
--- a/reactos/lib/rtl/actctx.c
+++ b/reactos/lib/rtl/actctx.c
@@ -2832,7 +2832,10 @@ RtlDeactivateActivationContextUnsafeFast(IN PRTL_CALLER_ALLOCATED_ACTIVATION_CON
     frame = &Frame->Frame;
 
     if (!frame)
+    {
+        DPRINT1("No top frame!\n");
         RtlRaiseStatus( STATUS_SXS_INVALID_DEACTIVATION );
+    }
 
     /* pop everything up to and including frame */
     NtCurrentTeb()->ActivationContextStackPointer->ActiveFrame = frame->Previous;