--- mongodb-src-r3.4.7/src/mongo/crypto/sha1_block_openssl.cpp.orig
+++ mongodb-src-r3.4.7/src/mongo/crypto/sha1_block_openssl.cpp
@@ -42,7 +42,7 @@
 #include <openssl/evp.h>
 #include <openssl/hmac.h>
 #include <openssl/sha.h>
-#if OPENSSL_VERSION_NUMBER < 0x10100000L
+#if OPENSSL_VERSION_NUMBER < 0x10100000L || defined(LIBRESSL_VERSION_NUMBER)
 namespace {
 // Copies of OpenSSL after 1.1.0 define new EVP digest routines. We must
 // polyfill used definitions to interact with older OpenSSL versions.
--- mongodb-src-r3.4.7/src/mongo/util/net/ssl_manager.cpp.orig
+++ mongodb-src-r3.4.7/src/mongo/util/net/ssl_manager.cpp
@@ -150,7 +150,7 @@
 #endif // MONGO_CONFIG_NEEDS_ASN1_ANY_DEFINITIONS
 // clang-format on
 
-#if OPENSSL_VERSION_NUMBER < 0x10100000L
+#if OPENSSL_VERSION_NUMBER < 0x10100000L || defined(LIBRESSL_VERSION_NUMBER)
 // Copies of OpenSSL after 1.1.0 define new functions for interaction with
 // X509 structure. We must polyfill used definitions to interact with older
 // OpenSSL versions.