diff --git a/config/lyxinclude.m4 b/config/lyxinclude.m4
index e4acd7b9ec..40f86abf70 100644
--- a/config/lyxinclude.m4
+++ b/config/lyxinclude.m4
@@ -686,6 +686,9 @@ AC_DEFUN([LYX_CHECK_MACOS_DEPLOYMENT_TARGET],[
   if test "${macos_deployment_target}" = "auto" ; then
     macos_deployment_target="10.10"
     case "$QTLIB_VERSION" in
+    5.12.*)
+      macos_deployment_target="10.12"
+      ;;
     6.*)
       macos_deployment_target="10.14"
       ;;