diff --git a/project/config/cfgdefs.sh b/project/config/cfgdefs.sh
index 6826af7..57a14b5 100644
--- a/project/config/cfgdefs.sh
+++ b/project/config/cfgdefs.sh
@@ -146,6 +146,7 @@ cfgdefs_output_custom_defs()
 cfgdefs_perform_common_tests()
 {
 	# headers
+	cfgtest_header_absence  'crypt.h'
 	cfgtest_header_absence  'stropts.h'
 	cfgtest_header_presence 'stdatomic.h'
 	cfgtest_header_presence 'endian.h'