diff --git a/configure.in b/configure.in
index e6382da9..21300898 100644
--- a/configure.in
+++ b/configure.in
@@ -29,7 +29,7 @@ AC_SUBST(LIBOBJS)
 
 AC_HAVE_FUNCS(getdtablesize sys_siglist _sys_siglist psignal \
 	      dup2 getcwd sigsetmask getgroups setlinebuf \
-	      setreuid setregid)
+	      setreuid setregid strerror)
 AC_ALLOCA
 AC_VFORK
 AC_SETVBUF_REVERSED