diff --git a/make/common/source_files.mk b/make/common/source_files.mk
index b479048a..9a4ba59b 100644
--- a/make/common/source_files.mk
+++ b/make/common/source_files.mk
@@ -98,6 +98,8 @@ CORE_OPENSSL_SOURCE_FILES = \
 # `CORE_OPENSSL_SOURCE_FILES` extension for POSIX build.
 CORE_OPENSSL_SOURCE_FILES_POSIX = \
     ../openssl/pbpal_add_system_certs_posix.c
+CORE_OPENSSL_SOURCE_FILES_NOT_DARWIN = \
+    ../lib/md5/md5.c
 
 # `CORE_OPENSSL_SOURCE_FILES` extension for Windows build.
 CORE_OPENSSL_SOURCE_FILES_WINDOWS = \
diff --git a/make/posix_source_files.mk b/make/posix_source_files.mk
index 27d801dd..6800281c 100644
--- a/make/posix_source_files.mk
+++ b/make/posix_source_files.mk
@@ -33,6 +33,10 @@ ifeq ($(OPENSSL),1)
         $(CORE_OPENSSL_SOURCE_FILES)       \
         $(CORE_OPENSSL_SOURCE_FILES_POSIX)
 
+	ifneq ($(shell uname),Darwin)
+		SOURCE_FILES += $(CORE_OPENSSL_SOURCE_FILES_NOT_DARWIN)
+	endif
+
     CALLBACK_SOURCE_FILES += \
         $(CALLBACK_CORE_OPENSSL_SOURCE_FILES)       \
         $(CALLBACK_CORE_OPENSSL_SOURCE_FILES_POSIX)