diff --git a/patches/bcrypt-Improvements/0027-bcrypt-Fix-BCryptEncrypt-with-AES_GCM-and-no-input-a.patch b/patches/bcrypt-Improvements/0027-bcrypt-Fix-BCryptEncrypt-with-AES_GCM-and-no-input-a.patch
new file mode 100644
index 00000000..85ef56a7
--- /dev/null
+++ b/patches/bcrypt-Improvements/0027-bcrypt-Fix-BCryptEncrypt-with-AES_GCM-and-no-input-a.patch
@@ -0,0 +1,63 @@
+From 9d4cfb266667d09430c5036ef127d30d5ac5ffbe Mon Sep 17 00:00:00 2001
+From: Andrew Wesie <awesie@gmail.com>
+Date: Mon, 1 May 2017 22:57:43 -0500
+Subject: bcrypt: Fix BCryptEncrypt with AES_GCM and no input and no output.
+
+Signed-off-by: Andrew Wesie <awesie@gmail.com>
+---
+ dlls/bcrypt/bcrypt_main.c  |  2 +-
+ dlls/bcrypt/tests/bcrypt.c | 18 ++++++++++++++++++
+ 2 files changed, 19 insertions(+), 1 deletion(-)
+
+diff --git a/dlls/bcrypt/bcrypt_main.c b/dlls/bcrypt/bcrypt_main.c
+index c25f1d1e99..d269083eca 100644
+--- a/dlls/bcrypt/bcrypt_main.c
++++ b/dlls/bcrypt/bcrypt_main.c
+@@ -1185,7 +1185,7 @@ NTSTATUS WINAPI BCryptEncrypt( BCRYPT_KEY_HANDLE handle, UCHAR *input, ULONG inp
+ 
+         *ret_len = input_len;
+         if (flags & BCRYPT_BLOCK_PADDING) return STATUS_INVALID_PARAMETER;
+-        if (!output) return STATUS_SUCCESS;
++        if (input && !output) return STATUS_SUCCESS;
+         if (output_len < *ret_len) return STATUS_BUFFER_TOO_SMALL;
+ 
+         if (auth_info->pbAuthData && (status = key_set_auth_data( key, auth_info->pbAuthData, auth_info->cbAuthData )))
+diff --git a/dlls/bcrypt/tests/bcrypt.c b/dlls/bcrypt/tests/bcrypt.c
+index 7f01529b3b..9f34a54978 100644
+--- a/dlls/bcrypt/tests/bcrypt.c
++++ b/dlls/bcrypt/tests/bcrypt.c
+@@ -913,6 +913,9 @@ static void test_BCryptEncrypt(void)
+         {0x9a,0x92,0x32,0x2c,0x61,0x2a,0xae,0xef,0x66,0x2a,0xfb,0x55,0xe9,0x48,0xdf,0xbd};
+     static UCHAR expected_tag3[] =
+         {0x17,0x9d,0xc0,0x7a,0xf0,0xcf,0xaa,0xd5,0x1c,0x11,0xc4,0x4b,0xd6,0xa3,0x3e,0x77};
++    static UCHAR expected_tag4[] =
++        {0x4c,0x42,0x83,0x9e,0x8d,0x40,0xf1,0x19,0xd6,0x2b,0x1c,0x66,0x03,0x2b,0x39,0x63};
++
+     BCRYPT_AUTHENTICATED_CIPHER_MODE_INFO auth_info;
+     UCHAR *buf, ciphertext[48], ivbuf[16], tag[16];
+     BCRYPT_AUTH_TAG_LENGTHS_STRUCT tag_length;
+@@ -1104,6 +1107,21 @@ static void test_BCryptEncrypt(void)
+     for (i = 0; i < 16; i++)
+         ok(tag[i] == expected_tag3[i], "%u: %02x != %02x\n", i, tag[i], expected_tag3[i]);
+ 
++    memset(tag, 0xff, sizeof(tag));
++    ret = pBCryptEncrypt(key, data2, 0, &auth_info, ivbuf, 16, NULL, 0, &size, 0);
++    ok(ret == STATUS_SUCCESS, "got %08x\n", ret);
++    ok(size == 0, "got %u\n", size);
++    for (i = 0; i < 16; i++)
++        ok(tag[i] == 0xff, "%u: %02x != %02x\n", i, tag[i], 0xff);
++
++    memset(tag, 0xff, sizeof(tag));
++    ret = pBCryptEncrypt(key, NULL, 0, &auth_info, ivbuf, 16, NULL, 0, &size, 0);
++    ok(ret == STATUS_SUCCESS, "got %08x\n", ret);
++    ok(size == 0, "got %u\n", size);
++    ok(!memcmp(tag, expected_tag4, sizeof(expected_tag4)), "wrong tag\n");
++    for (i = 0; i < 16; i++)
++        ok(tag[i] == expected_tag4[i], "%u: %02x != %02x\n", i, tag[i], expected_tag4[i]);
++
+     /* test with padding */
+     memcpy(ivbuf, iv, sizeof(iv));
+     memset(ciphertext, 0, sizeof(ciphertext));
+-- 
+2.12.2
+
diff --git a/patches/patchinstall.sh b/patches/patchinstall.sh
index d19c6161..b81e2ce6 100755
--- a/patches/patchinstall.sh
+++ b/patches/patchinstall.sh
@@ -2944,6 +2944,7 @@ if test "$enable_bcrypt_Improvements" -eq 1; then
 	patch_apply bcrypt-Improvements/0024-bcrypt-tests-Add-tests-for-auth-data-in-AES-GCM-mode.patch
 	patch_apply bcrypt-Improvements/0025-bcrypt-Avoid-crash-in-tests-when-compiling-without-g.patch
 	patch_apply bcrypt-Improvements/0026-bcrypt-Implement-support-for-ECB-chain-mode.patch
+	patch_apply bcrypt-Improvements/0027-bcrypt-Fix-BCryptEncrypt-with-AES_GCM-and-no-input-a.patch
 	(
 		printf '%s\n' '+    { "Hans Leidekker", "bcrypt: Add AES provider.", 1 },';
 		printf '%s\n' '+    { "Michael Müller", "bcrypt: Fix handling of padding when input size equals block size for AES.", 1 },';
@@ -2966,6 +2967,7 @@ if test "$enable_bcrypt_Improvements" -eq 1; then
 		printf '%s\n' '+    { "Sebastian Lackner", "bcrypt/tests: Add tests for auth data in AES GCM mode.", 1 },';
 		printf '%s\n' '+    { "Sebastian Lackner", "bcrypt: Avoid crash in tests when compiling without gnutls support.", 1 },';
 		printf '%s\n' '+    { "Sebastian Lackner", "bcrypt: Implement support for ECB chain mode.", 1 },';
+		printf '%s\n' '+    { "Andrew Wesie", "bcrypt: Fix BCryptEncrypt with AES_GCM and no input and no output.", 1 },';
 	) >> "$patchlist"
 fi