diff --git a/ntoskrnl/include/internal/cm_x.h b/ntoskrnl/include/internal/cm_x.h
index b9e561952c3..daf7d67643b 100644
--- a/ntoskrnl/include/internal/cm_x.h
+++ b/ntoskrnl/include/internal/cm_x.h
@@ -12,6 +12,12 @@
 #define GET_HASH_KEY(ConvKey)                                       \
     ((CMP_HASH_IRRATIONAL * (ConvKey)) % CMP_HASH_PRIME)
 
+//
+// Computes the hashkey of a character
+//
+#define COMPUTE_HASH_CHAR(ConvKey, Char)                            \
+    (37 * ConvKey + RtlUpcaseUnicodeChar(Char))
+
 //
 // Returns the index into the hash table, or the entry itself
 //