diff --git a/tests/fexist.c b/tests/fexist.c
index a18b71f..39e2daf 100644
--- a/tests/fexist.c
+++ b/tests/fexist.c
@@ -1,3 +1,4 @@
+#include <err.h>
 #include "check.h"
 
 int main(void)
diff --git a/tests/fisdir.c b/tests/fisdir.c
index 307aed6..7ab6238 100644
--- a/tests/fisdir.c
+++ b/tests/fisdir.c
@@ -1,3 +1,4 @@
+#include <err.h>
 #include "check.h"
 
 int main(void)
diff --git a/tests/pidfile.c b/tests/pidfile.c
index bd63b12..3bb1dab 100644
--- a/tests/pidfile.c
+++ b/tests/pidfile.c
@@ -1,3 +1,4 @@
+#include <err.h>
 #include <paths.h>
 #include <signal.h>
 #include <stdarg.h>