diff --git a/lib/libcasper/services/cap_dns/tests/Makefile b/lib/libcasper/services/cap_dns/tests/Makefile
index 20049a06ccb..55c163bbdb4 100644
--- a/lib/libcasper/services/cap_dns/tests/Makefile
+++ b/lib/libcasper/services/cap_dns/tests/Makefile
@@ -7,6 +7,7 @@ TAP_TESTS_C=	dns_test
 .if ${MK_CASPER} != "no"
 LIBADD+=	casper
 LIBADD+=	cap_dns
+CFLAGS+=-DWITH_CASPER
 .endif
 LIBADD+=	nv
 
diff --git a/lib/libcasper/services/cap_grp/tests/Makefile b/lib/libcasper/services/cap_grp/tests/Makefile
index b1b7e05d0ee..ff2f2f18e25 100644
--- a/lib/libcasper/services/cap_grp/tests/Makefile
+++ b/lib/libcasper/services/cap_grp/tests/Makefile
@@ -7,6 +7,7 @@ TAP_TESTS_C=	grp_test
 .if ${MK_CASPER} != "no"
 LIBADD+=	casper
 LIBADD+=	cap_grp
+CFLAGS+=-DWITH_CASPER
 .endif
 LIBADD+=	nv
 
diff --git a/lib/libcasper/services/cap_pwd/tests/Makefile b/lib/libcasper/services/cap_pwd/tests/Makefile
index b4e75d346fc..d010cc45efd 100644
--- a/lib/libcasper/services/cap_pwd/tests/Makefile
+++ b/lib/libcasper/services/cap_pwd/tests/Makefile
@@ -7,6 +7,7 @@ TAP_TESTS_C=	pwd_test
 .if ${MK_CASPER} != "no"
 LIBADD+=	casper
 LIBADD+=	cap_pwd
+CFLAGS+=-DWITH_CASPER
 .endif
 LIBADD+=	nv
 
diff --git a/lib/libcasper/services/cap_sysctl/tests/Makefile b/lib/libcasper/services/cap_sysctl/tests/Makefile
index b11c45fb656..3afd703846d 100644
--- a/lib/libcasper/services/cap_sysctl/tests/Makefile
+++ b/lib/libcasper/services/cap_sysctl/tests/Makefile
@@ -7,6 +7,7 @@ TAP_TESTS_C=	sysctl_test
 .if ${MK_CASPER} != "no"
 LIBADD+=	casper
 LIBADD+=	cap_sysctl
+CFLAGS+=-DWITH_CASPER
 .endif
 LIBADD+=	nv