diff --git a/src/acl/ConnMark.cc b/src/acl/ConnMark.cc
index 1fdae0c..213cf39 100644
--- a/src/acl/ConnMark.cc
+++ b/src/acl/ConnMark.cc
@@ -16,6 +16,7 @@
 #include "debug/Stream.h"
 #include "http/Stream.h"
 #include "sbuf/Stream.h"
+#include <limits>
 
 bool
 Acl::ConnMark::empty() const
diff --git a/src/security/ServerOptions.cc b/src/security/ServerOptions.cc
index 5cd81ab..3f73892 100644
--- a/src/security/ServerOptions.cc
+++ b/src/security/ServerOptions.cc
@@ -6,6 +6,7 @@
  * Please see the COPYING and CONTRIBUTORS files for details.
  */
 
+#include <limits>
 #include "squid.h"
 #include "anyp/PortCfg.h"
 #include "base/Packable.h"