diff --git a/dlls/imm32/imm.c b/dlls/imm32/imm.c
index 284d49eb840..5aee6ea78f7 100644
--- a/dlls/imm32/imm.c
+++ b/dlls/imm32/imm.c
@@ -2665,7 +2665,8 @@ BOOL WINAPI ImmUnlockIMCC(HIMCC imcc)
     IMCCInternal *internal;
     internal = imcc;
 
-    internal->dwLock --;
+    if (internal->dwLock)
+        internal->dwLock --;
     return (internal->dwLock!=0);
 }
 
diff --git a/dlls/imm32/tests/imm32.c b/dlls/imm32/tests/imm32.c
index 9d41cc78208..26101a4764f 100644
--- a/dlls/imm32/tests/imm32.c
+++ b/dlls/imm32/tests/imm32.c
@@ -728,9 +728,9 @@ static void test_ImmGetIMCCLockCount(void)
     count = ImmGetIMCCLockCount(imcc);
     ok(count == 0, "expect 0, returned %d\n", count);
     ret = ImmUnlockIMCC(imcc);
-    todo_wine ok(ret == FALSE, "expect FALSE, ret %d\n", ret);
+    ok(ret == FALSE, "expect FALSE, ret %d\n", ret);
     count = ImmGetIMCCLockCount(imcc);
-    todo_wine ok(count == 0, "expect 0, returned %d\n", count);
+    ok(count == 0, "expect 0, returned %d\n", count);
     ImmDestroyIMCC(imcc);
 }