diff --git a/decrepit/evp/CMakeLists.txt b/decrepit/evp/CMakeLists.txt
index ee3bf33b..e631a9a9 100644
--- a/decrepit/evp/CMakeLists.txt
+++ b/decrepit/evp/CMakeLists.txt
@@ -5,5 +5,6 @@ add_library(
 
   OBJECT
 
+  dss1.c
   evp_do_all.c
 )
diff --git a/decrepit/evp/dss1.c b/decrepit/evp/dss1.c
new file mode 100644
index 00000000..9c370acb
--- /dev/null
+++ b/decrepit/evp/dss1.c
@@ -0,0 +1,20 @@
+/* Copyright (c) 2016, 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/digest.h>
+
+
+const EVP_MD *EVP_dss1(void) {
+  return EVP_sha1();
+}
diff --git a/include/openssl/digest.h b/include/openssl/digest.h
index db3ead71..07ea07a6 100644
--- a/include/openssl/digest.h
+++ b/include/openssl/digest.h
@@ -212,6 +212,12 @@ OPENSSL_EXPORT int EVP_add_digest(const EVP_MD *digest);
  * |name|, or NULL if the name is unknown. */
 OPENSSL_EXPORT const EVP_MD *EVP_get_digestbyname(const char *);
 
+/* EVP_dss1 returns the value of EVP_sha1(). This was provided by OpenSSL to
+ * specifiy the original DSA signatures, which were fixed to use SHA-1. Note,
+ * however, that attempting to sign or verify DSA signatures with the EVP
+ * interface will always fail. */
+OPENSSL_EXPORT const EVP_MD *EVP_dss1(void);
+
 
 /* Digest operation accessors. */