diff --git a/src/tools/Makefile.am b/src/tools/Makefile.am
index 55beb631..4915ab90 100644
--- a/src/tools/Makefile.am
+++ b/src/tools/Makefile.am
@@ -98,7 +98,7 @@ endif
 
 opensc_notify_SOURCES = opensc-notify.c opensc-notify-cmdline.c
 opensc_notify_LDADD = $(top_builddir)/src/libopensc/libopensc.la $(OPTIONAL_NOTIFY_LIBS)
-opensc_notify_CFLAGS = -I$(top_srcdir)/src $(OPTIONAL_NOTIFY_CFLAGS)
+opensc_notify_CFLAGS = -I$(top_srcdir)/src $(PTHREAD_CFLAGS) $(OPTIONAL_NOTIFY_CFLAGS)
 opensc_notify_CFLAGS += -Wno-unused-but-set-variable
 if HAVE_UNKNOWN_WARNING_OPTION
 opensc_notify_CFLAGS += -Wno-unknown-warning-option