diff --git a/cddl/usr.sbin/zfsd/case_file.cc b/cddl/usr.sbin/zfsd/case_file.cc
index 852767aeb227..69086b4a7255 100644
--- a/cddl/usr.sbin/zfsd/case_file.cc
+++ b/cddl/usr.sbin/zfsd/case_file.cc
@@ -49,6 +49,7 @@
 #include <iomanip>
 #include <fstream>
 #include <functional>
+#include <algorithm>
 #include <sstream>
 #include <syslog.h>
 #include <unistd.h>