diff --git a/dlls/ncrypt/main.c b/dlls/ncrypt/main.c
index 1e8fe93244c..6022d20ca0c 100644
--- a/dlls/ncrypt/main.c
+++ b/dlls/ncrypt/main.c
@@ -89,6 +89,12 @@ SECURITY_STATUS WINAPI NCryptFinalizeKey(NCRYPT_KEY_HANDLE key, DWORD flags)
     return NTE_NOT_SUPPORTED;
 }
 
+SECURITY_STATUS WINAPI NCryptFreeBuffer(PVOID buf)
+{
+    FIXME("(%p): stub\n", buf);
+    return NTE_NOT_SUPPORTED;
+}
+
 SECURITY_STATUS WINAPI NCryptFreeObject(NCRYPT_HANDLE object)
 {
     FIXME("(0x%lx): stub\n", object);
diff --git a/dlls/ncrypt/ncrypt.spec b/dlls/ncrypt/ncrypt.spec
index d4482d5b409..1c06935beda 100644
--- a/dlls/ncrypt/ncrypt.spec
+++ b/dlls/ncrypt/ncrypt.spec
@@ -72,7 +72,7 @@
 @ stub NCryptEnumStorageProviders
 @ stub NCryptExportKey
 @ stdcall NCryptFinalizeKey(long long)
-@ stub NCryptFreeBuffer
+@ stdcall NCryptFreeBuffer(ptr)
 @ stdcall NCryptFreeObject(long)
 @ stub NCryptGetProperty
 @ stub NCryptGetProtectionDescriptorInfo