diff --git a/ntoskrnl/cc/cacheman.c b/ntoskrnl/cc/cacheman.c
index 9ef906ee43e..a2f9a9bb44a 100644
--- a/ntoskrnl/cc/cacheman.c
+++ b/ntoskrnl/cc/cacheman.c
@@ -228,7 +228,7 @@ CcScheduleReadAhead (
         /* It's active now!
          * Be careful with the mask, you don't want to mess with node code
          */
-        InterlockedOr((volatile long *)&PrivateCacheMap->UlongFlags, 0x10000);
+        InterlockedOr((volatile long *)&PrivateCacheMap->UlongFlags, PRIVATE_CACHE_MAP_READ_AHEAD_ACTIVE);
         KeReleaseSpinLock(&PrivateCacheMap->ReadAheadSpinLock, OldIrql);
 
         /* Get a work item */
@@ -250,7 +250,7 @@ CcScheduleReadAhead (
 
         /* Fail path: lock again, and revert read ahead active */
         KeAcquireSpinLock(&PrivateCacheMap->ReadAheadSpinLock, &OldIrql);
-        InterlockedAnd((volatile long *)&PrivateCacheMap->UlongFlags, 0xFFFEFFFF);
+        InterlockedAnd((volatile long *)&PrivateCacheMap->UlongFlags, ~PRIVATE_CACHE_MAP_READ_AHEAD_ACTIVE);
     }
 
     /* Done (fail) */
diff --git a/ntoskrnl/cc/copy.c b/ntoskrnl/cc/copy.c
index a90734000e3..43287774a3a 100644
--- a/ntoskrnl/cc/copy.c
+++ b/ntoskrnl/cc/copy.c
@@ -594,7 +594,7 @@ Clear:
     {
         /* Mark read ahead as unactive */
         KeAcquireSpinLockAtDpcLevel(&PrivateCacheMap->ReadAheadSpinLock);
-        InterlockedAnd((volatile long *)&PrivateCacheMap->UlongFlags, 0xFFFEFFFF);
+        InterlockedAnd((volatile long *)&PrivateCacheMap->UlongFlags, ~PRIVATE_CACHE_MAP_READ_AHEAD_ACTIVE);
         KeReleaseSpinLockFromDpcLevel(&PrivateCacheMap->ReadAheadSpinLock);
     }
     KeReleaseQueuedSpinLock(LockQueueMasterLock, OldIrql);
diff --git a/sdk/include/ndk/cctypes.h b/sdk/include/ndk/cctypes.h
index c07e96732a5..ef5a57eadb0 100644
--- a/sdk/include/ndk/cctypes.h
+++ b/sdk/include/ndk/cctypes.h
@@ -61,6 +61,9 @@ typedef struct _PRIVATE_CACHE_MAP_FLAGS
     ULONG Available:14;
 } PRIVATE_CACHE_MAP_FLAGS;
 
+#define PRIVATE_CACHE_MAP_READ_AHEAD_ACTIVE     (1 << 16)
+#define PRIVATE_CACHE_MAP_READ_AHEAD_ENABLED    (1 << 17)
+
 typedef struct _PRIVATE_CACHE_MAP
 {
     union