diff --git a/apps/openssl/CMakeLists.txt b/apps/openssl/CMakeLists.txt
index db63ecf..6d89c06 100644
--- a/apps/openssl/CMakeLists.txt
+++ b/apps/openssl/CMakeLists.txt
@@ -67,6 +67,13 @@ else()
 	set(OPENSSL_SRC ${OPENSSL_SRC} compat/strtonum.c)
 endif()
 
+if(CMAKE_SYSTEM_NAME MATCHES "Darwin")
+        check_function_exists(clock_gettime HAVE_CLOCK_GETTIME)
+        if(NOT HAVE_CLOCK_GETTIME)
+                set(OPENSSL_SRC ${OPENSSL_SRC} compat/clock_gettime_osx.c)
+        endif()
+endif()
+
 add_executable(openssl ${OPENSSL_SRC})
 target_include_directories(openssl PRIVATE . ../../include/compat)
 target_link_libraries(openssl ${OPENSSL_LIBS})