1 files changed, 2 insertions, 1 deletions

diff --git a/apps/ocspcheck/CMakeLists.txt b/apps/ocspcheck/CMakeLists.txt
index b960a81..43b091a 100644
--- a/apps/ocspcheck/CMakeLists.txt
+++ b/apps/ocspcheck/CMakeLists.txt
@@ -14,7 +14,8 @@ else()
 endif()
 
 check_function_exists(strtonum HAVE_STRTONUM)
-if(HAVE_STRTONUM)
+if(HAVE_STRTONUM AND CMAKE_SYSTEM_NAME MATCHES "Darwin" AND
+    CMAKE_HOST_SYSTEM_VERSION VERSION_GREATER_EQUAL 20)
         add_definitions(-DHAVE_STRTONUM)
 else()
         set(OCSPCHECK_SRC ${OCSPCHECK_SRC} compat/strtonum.c)