diff --git a/xtoskrnl/includes/rtli.h b/xtoskrnl/includes/rtli.h
index 618aa8a..34f8efd 100644
--- a/xtoskrnl/includes/rtli.h
+++ b/xtoskrnl/includes/rtli.h
@@ -33,6 +33,16 @@ LONG_PTR
 RtlAtomicAnd64(IN VOLATILE PLONG_PTR Address,
                IN LONG_PTR Mask);
 
+XTFASTCALL
+UCHAR
+RtlAtomicBitTestAndSet(IN VOLATILE PLONG Base,
+                       IN LONG Offset);
+
+XTFASTCALL
+UCHAR
+RtlAtomicBitTestAndSet64(IN VOLATILE PLONGLONG Base,
+                         IN LONGLONG Offset);
+
 XTFASTCALL
 CHAR
 RtlAtomicCompareExchange8(IN VOLATILE PCHAR Address,
diff --git a/xtoskrnl/rtl/atomic.c b/xtoskrnl/rtl/atomic.c
index d2d99b4..46b2fe8 100644
--- a/xtoskrnl/rtl/atomic.c
+++ b/xtoskrnl/rtl/atomic.c
@@ -93,6 +93,48 @@ RtlAtomicAnd64(IN VOLATILE PLONG_PTR Address,
     return __sync_fetch_and_and(Address, Mask);
 }
 
+/**
+ * Performs an atomic test of the specified bit of the specified long value and sets it to 1.
+ *
+ * @param Base
+ *        Specifies a pointer to the variable.
+ *
+ * @param Offset
+ *        Specifies the bit position to be tested.
+ *
+ * @return Returns a value of the specified bit.
+ *
+ * @since XT 1.0
+ */
+XTFASTCALL
+UCHAR
+RtlAtomicBitTestAndSet(IN VOLATILE PLONG Base,
+                       IN LONG Offset)
+{
+    return (__atomic_fetch_or(Base, 1l << Offset, __ATOMIC_SEQ_CST) >> Offset) & 1;
+}
+
+/**
+ * Performs an atomic test of the specified bit of the specified 64-bit long value and sets it to 1.
+ *
+ * @param Base
+ *        Specifies a pointer to the variable.
+ *
+ * @param Offset
+ *        Specifies the bit position to be tested.
+ *
+ * @return Returns a value of the specified bit.
+ *
+ * @since XT 1.0
+ */
+XTFASTCALL
+UCHAR
+RtlAtomicBitTestAndSet64(IN VOLATILE PLONGLONG Base,
+                         IN LONGLONG Offset)
+{
+    return (__atomic_fetch_or(Base, 1ll << Offset, __ATOMIC_SEQ_CST) >> Offset) & 1;
+}
+
 /**
  * Performs atomically compare exchange operation on the 8-bit value.
  *