diff --git a/bin/otpkey/Makefile.am b/bin/otpkey/Makefile.am
index ab34c81..08c284d 100644
--- a/bin/otpkey/Makefile.am
+++ b/bin/otpkey/Makefile.am
@@ -1,8 +1,16 @@
 AM_CPPFLAGS = -I$(top_srcdir)/include
 
+libotp = $(top_builddir)/lib/otp/libcryb-otp.la
+
 bin_PROGRAMS = otpkey
 
 otpkey_SOURCES = otpkey.c
+
+otpkey_CFLAGS = \
+	$(CRYB_CORE_CFLAGS)
+
+otpkey_LDADD = $(libotp)
+
 dist_man1_MANS = otpkey.1
 
 if WITH_SETUID
diff --git a/lib/otp/Makefile.am b/lib/otp/Makefile.am
index 02223c2..5071656 100644
--- a/lib/otp/Makefile.am
+++ b/lib/otp/Makefile.am
@@ -6,6 +6,10 @@ libcryb_otp_la_SOURCES = \
 	\
 	cryb_otp.c
 
+libcryb_otp_la_CFLAGS = \
+	 $(CRYB_CORE_CFLAGS) \
+	 $(CRYB_OATH_CFLAGS)
+
 libcryb_otp_la_LIBADD = \
 	$(CRYB_CORE_LIBS) \
 	$(CRYB_OATH_LIBS)
diff --git a/libexec/login_otp/Makefile.am b/libexec/login_otp/Makefile.am
index cb2a152..eb86179 100644
--- a/libexec/login_otp/Makefile.am
+++ b/libexec/login_otp/Makefile.am
@@ -5,6 +5,10 @@ libotp = $(top_builddir)/lib/otp/libcryb-otp.la
 libexec_PROGRAMS = login_otp
 
 login_otp_SOURCES = login_otp.c
+
+login_otp_CFLAGS = \
+	$(CRYB_CORE_CFLAGS)
+
 login_otp_LDADD = $(libotp)
 
 dist_man8_MANS = login_otp.8
diff --git a/pam/pam_otp/Makefile.am b/pam/pam_otp/Makefile.am
index 1605e33..9ba0e28 100644
--- a/pam/pam_otp/Makefile.am
+++ b/pam/pam_otp/Makefile.am
@@ -6,9 +6,15 @@ moduledir = $(libdir)
 module_LTLIBRARIES = pam_otp.la
 
 pam_otp_la_SOURCES = pam_otp.c
+
+pam_otp_la_CFLAGS = \
+	$(CRYB_CORE_CFLAGS)
+
 pam_otp_la_LIBADD = \
 	$(libotp) \
 	$(PAM_LIBS)
-pam_otp_la_LDFLAGS = -no-undefined -module -export-symbols-regex '^pam_sm_'
+
+pam_otp_la_LDFLAGS = \
+	-no-undefined -module -export-symbols-regex '^pam_sm_'
 
 dist_man8_MANS = pam_otp.8
diff --git a/sbin/otpradiusd/Makefile.am b/sbin/otpradiusd/Makefile.am
index 72723f7..66b008d 100644
--- a/sbin/otpradiusd/Makefile.am
+++ b/sbin/otpradiusd/Makefile.am
@@ -1,6 +1,14 @@
 AM_CPPFLAGS = -I$(top_srcdir)/include
 
+libotp = $(top_builddir)/lib/otp/libcryb-otp.la
+
 sbin_PROGRAMS = otpradiusd
 
 otpradiusd_SOURCES = otpradiusd.c
+
+otpradiusd_CFLAGS = \
+	$(CRYB_CORE_CFLAGS)
+
+otpradiusd_LDADD = $(libotp)
+
 dist_man8_MANS = otpradiusd.8
diff --git a/t/Makefile.am b/t/Makefile.am
index 0cac1d9..3558472 100644
--- a/t/Makefile.am
+++ b/t/Makefile.am
@@ -12,7 +12,7 @@ TESTS =
 # c++ header test
 TESTS += t_cxx
 t_cxx_SOURCES = t_cxx.cc
-t_cxx_CPPFLAGS = $(AM_CPPFLAGS)
+t_cxx_CPPFLAGS = $(AM_CPPFLAGS) $(CRYB_CORE_CFLAGS)
 t_cxx_LDADD =
 if OTP_LIB
 t_cxx_CPPFLAGS += -DWITH_OTP_LIB