diff --git a/dlls/bcrypt/bcrypt.spec b/dlls/bcrypt/bcrypt.spec
index c96ed2a90e7..4a53df63fc9 100644
--- a/dlls/bcrypt/bcrypt.spec
+++ b/dlls/bcrypt/bcrypt.spec
@@ -5,7 +5,7 @@
 @ stub BCryptConfigureContextFunction
 @ stub BCryptCreateContext
 @ stdcall BCryptCreateHash(ptr ptr ptr long ptr long long)
-@ stub BCryptDecrypt
+@ stdcall BCryptDecrypt(ptr ptr long ptr ptr long ptr long ptr long)
 @ stub BCryptDeleteContext
 @ stub BCryptDeriveKey
 @ stdcall BCryptDestroyHash(ptr)
diff --git a/dlls/bcrypt/bcrypt_main.c b/dlls/bcrypt/bcrypt_main.c
index ccab676c1ae..9f9c8c1283e 100644
--- a/dlls/bcrypt/bcrypt_main.c
+++ b/dlls/bcrypt/bcrypt_main.c
@@ -693,6 +693,15 @@ NTSTATUS WINAPI BCryptEncrypt( BCRYPT_KEY_HANDLE handle, UCHAR *input, ULONG inp
     return STATUS_NOT_IMPLEMENTED;
 }
 
+NTSTATUS WINAPI BCryptDecrypt( BCRYPT_KEY_HANDLE handle, UCHAR *input, ULONG input_len,
+                               void *padding, UCHAR *iv, ULONG iv_len, UCHAR *output,
+                               ULONG output_len, ULONG *ret_len, ULONG flags )
+{
+    FIXME( "%p, %p, %u, %p, %p, %u, %p, %u, %p, %08x\n", handle, input, input_len,
+           padding, iv, iv_len, output, output_len, ret_len, flags );
+    return STATUS_NOT_IMPLEMENTED;
+}
+
 BOOL WINAPI DllMain( HINSTANCE hinst, DWORD reason, LPVOID reserved )
 {
     switch (reason)
diff --git a/dlls/ncrypt/ncrypt.spec b/dlls/ncrypt/ncrypt.spec
index 62a8128c1ad..739b1cea9a0 100644
--- a/dlls/ncrypt/ncrypt.spec
+++ b/dlls/ncrypt/ncrypt.spec
@@ -5,7 +5,7 @@
 @ stub BCryptConfigureContextFunction
 @ stub BCryptCreateContext
 @ stdcall BCryptCreateHash(ptr ptr ptr long ptr long long) bcrypt.BCryptCreateHash
-@ stub BCryptDecrypt
+@ stdcall BCryptDecrypt(ptr ptr long ptr ptr long ptr long ptr long) bcrypt.BCryptDecrypt
 @ stub BCryptDeleteContext
 @ stub BCryptDeriveKey
 @ stub BCryptDeriveKeyCapi