diff --git a/crypto/CMakeLists.txt b/crypto/CMakeLists.txt
index 2b81faa..8565977 100644
--- a/crypto/CMakeLists.txt
+++ b/crypto/CMakeLists.txt
@@ -456,6 +456,7 @@
   fipsmodule/ec/ec_test.cc
   fipsmodule/ec/p256-x86_64_test.cc
   fipsmodule/ecdsa/ecdsa_test.cc
+  fipsmodule/md5/md5_test.cc
   fipsmodule/modes/gcm_test.cc
   fipsmodule/rand/ctrdrbg_test.cc
   fipsmodule/sha/sha_test.cc
diff --git a/crypto/fipsmodule/md5/asm/md5-x86_64.pl b/crypto/fipsmodule/md5/asm/md5-x86_64.pl
index 568f4f5..6eb33c0 100644
--- a/crypto/fipsmodule/md5/asm/md5-x86_64.pl
+++ b/crypto/fipsmodule/md5/asm/md5-x86_64.pl
@@ -130,11 +130,17 @@
 .globl md5_block_asm_data_order
 .type md5_block_asm_data_order,\@function,3
 md5_block_asm_data_order:
+.cfi_startproc
 	push	%rbp
+.cfi_push	rbp
 	push	%rbx
+.cfi_push	rbx
 	push	%r12
+.cfi_push	r12
 	push	%r14
+.cfi_push	r14
 	push	%r15
+.cfi_push	r15
 .Lprologue:
 
 	# rdi = arg #1 (ctx, MD5_CTX pointer)
@@ -251,13 +257,20 @@
 	mov	%edx,		3*4(%rbp)	# ctx->D = D
 
 	mov	(%rsp),%r15
+.cfi_restore r15
 	mov	8(%rsp),%r14
+.cfi_restore r14
 	mov	16(%rsp),%r12
+.cfi_restore r12
 	mov	24(%rsp),%rbx
+.cfi_restore rbx
 	mov	32(%rsp),%rbp
+.cfi_restore rbp
 	add	\$40,%rsp
+.cfi_adjust_cfa_offset	-40
 .Lepilogue:
 	ret
+.cfi_endproc
 .size md5_block_asm_data_order,.-md5_block_asm_data_order
 EOF
 
diff --git a/crypto/fipsmodule/md5/internal.h b/crypto/fipsmodule/md5/internal.h
new file mode 100644
index 0000000..9ee9f13
--- /dev/null
+++ b/crypto/fipsmodule/md5/internal.h
@@ -0,0 +1,37 @@
+/* Copyright (c) 2018, Google Inc.
+ *
+ * Permission to use, copy, modify, and/or distribute this software for any
+ * purpose with or without fee is hereby granted, provided that the above
+ * copyright notice and this permission notice appear in all copies.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
+ * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
+ * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY
+ * SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
+ * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN ACTION
+ * OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF OR IN
+ * CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE. */
+
+#ifndef OPENSSL_HEADER_MD5_INTERNAL_H
+#define OPENSSL_HEADER_MD5_INTERNAL_H
+
+#include <openssl/base.h>
+
+#if defined(__cplusplus)
+extern "C" {
+#endif
+
+
+#if !defined(OPENSSL_NO_ASM) && \
+    (defined(OPENSSL_X86_64) || defined(OPENSSL_X86))
+#define MD5_ASM
+extern void md5_block_asm_data_order(uint32_t *state, const uint8_t *data,
+                                     size_t num);
+#endif
+
+
+#if defined(__cplusplus)
+}  // extern "C"
+#endif
+
+#endif  // OPENSSL_HEADER_MD5_INTERNAL_H
diff --git a/crypto/fipsmodule/md5/md5.c b/crypto/fipsmodule/md5/md5.c
index 370b42a..66c65a6 100644
--- a/crypto/fipsmodule/md5/md5.c
+++ b/crypto/fipsmodule/md5/md5.c
@@ -60,6 +60,7 @@
 
 #include <openssl/mem.h>
 
+#include "internal.h"
 #include "../../internal.h"
 
 
@@ -81,12 +82,8 @@
   return 1;
 }
 
-#if !defined(OPENSSL_NO_ASM) && \
-    (defined(OPENSSL_X86_64) || defined(OPENSSL_X86))
-#define MD5_ASM
+#if defined(MD5_ASM)
 #define md5_block_data_order md5_block_asm_data_order
-extern void md5_block_data_order(uint32_t *state, const uint8_t *data,
-                                 size_t num);
 #else
 static void md5_block_data_order(uint32_t *state, const uint8_t *data,
                                  size_t num);
diff --git a/crypto/fipsmodule/md5/md5_test.cc b/crypto/fipsmodule/md5/md5_test.cc
new file mode 100644
index 0000000..7df5bb2
--- /dev/null
+++ b/crypto/fipsmodule/md5/md5_test.cc
@@ -0,0 +1,34 @@
+/* Copyright (c) 2018, Google Inc.
+ *
+ * Permission to use, copy, modify, and/or distribute this software for any
+ * purpose with or without fee is hereby granted, provided that the above
+ * copyright notice and this permission notice appear in all copies.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
+ * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
+ * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY
+ * SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
+ * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN ACTION
+ * OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF OR IN
+ * CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE. */
+
+#include <openssl/md5.h>
+
+#include <gtest/gtest.h>
+
+#include "internal.h"
+#include "../../test/abi_test.h"
+
+
+#if defined(MD5_ASM) && defined(SUPPORTS_ABI_TEST)
+TEST(MD5Test, ABI) {
+  MD5_CTX ctx;
+  MD5_Init(&ctx);
+
+  static const uint8_t kBuf[MD5_CBLOCK * 8] = {0};
+  CHECK_ABI(md5_block_asm_data_order, ctx.h, kBuf, 1);
+  CHECK_ABI(md5_block_asm_data_order, ctx.h, kBuf, 2);
+  CHECK_ABI(md5_block_asm_data_order, ctx.h, kBuf, 4);
+  CHECK_ABI(md5_block_asm_data_order, ctx.h, kBuf, 8);
+}
+#endif  // MD5_ASM && SUPPORTS_ABI_TEST