diff --git a/crypto/engine/CMakeLists.txt b/crypto/engine/CMakeLists.txt
index 5126e2a..5458ff5 100644
--- a/crypto/engine/CMakeLists.txt
+++ b/crypto/engine/CMakeLists.txt
@@ -6,4 +6,5 @@
 	OBJECT
 
 	engine.c
+	engine_error.c
 )
diff --git a/crypto/engine/engine.c b/crypto/engine/engine.c
index c9b8823..1453e61 100644
--- a/crypto/engine/engine.c
+++ b/crypto/engine/engine.c
@@ -17,6 +17,7 @@
 #include <openssl/dh.h>
 #include <openssl/dsa.h>
 #include <openssl/ec_key.h>
+#include <openssl/err.h>
 #include <openssl/mem.h>
 #include <openssl/rsa.h>
 #include <openssl/thread.h>
@@ -131,3 +132,5 @@
     OPENSSL_free(method);
   }
 }
+
+OPENSSL_DECLARE_ERROR_REASON(ENGINE, OPERATION_NOT_SUPPORTED);
diff --git a/crypto/engine/engine_error.c b/crypto/engine/engine_error.c
new file mode 100644
index 0000000..9f65f70
--- /dev/null
+++ b/crypto/engine/engine_error.c
@@ -0,0 +1,22 @@
+/* Copyright (c) 2014, 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/err.h>
+
+#include <openssl/engine.h>
+
+const ERR_STRING_DATA ENGINE_error_string_data[] = {
+  {ERR_PACK(ERR_LIB_ENGINE, 0, ENGINE_R_OPERATION_NOT_SUPPORTED), "OPERATION_NOT_SUPPORTED"},
+  {0, NULL},
+};
diff --git a/crypto/err/err.c b/crypto/err/err.c
index 5a371a5..3c5ea99 100644
--- a/crypto/err/err.c
+++ b/crypto/err/err.c
@@ -699,6 +699,7 @@
 extern const ERR_STRING_DATA ECDH_error_string_data[];
 extern const ERR_STRING_DATA ECDSA_error_string_data[];
 extern const ERR_STRING_DATA EC_error_string_data[];
+extern const ERR_STRING_DATA ENGINE_error_string_data[];
 extern const ERR_STRING_DATA EVP_error_string_data[];
 extern const ERR_STRING_DATA OBJ_error_string_data[];
 extern const ERR_STRING_DATA PEM_error_string_data[];
@@ -752,6 +753,7 @@
   ERR_load_strings(ECDH_error_string_data);
   ERR_load_strings(ECDSA_error_string_data);
   ERR_load_strings(EC_error_string_data);
+  ERR_load_strings(ENGINE_error_string_data);
   ERR_load_strings(EVP_error_string_data);
   ERR_load_strings(OBJ_error_string_data);
   ERR_load_strings(PEM_error_string_data);
diff --git a/include/openssl/engine.h b/include/openssl/engine.h
index 367e98e..4a4f37d 100644
--- a/include/openssl/engine.h
+++ b/include/openssl/engine.h
@@ -100,4 +100,6 @@
 }  /* extern C */
 #endif
 
+#define ENGINE_R_OPERATION_NOT_SUPPORTED 100
+
 #endif  /* OPENSSL_HEADER_ENGINE_H */