diff --git a/src/logging.cc b/src/logging.cc
index 404afc55f..0a5df057b 100644
--- a/src/logging.cc
+++ b/src/logging.cc
@@ -60,6 +60,7 @@
 #include <cerrno>                   // for errno
 #include <sstream>
 #include <regex>
+#include <cctype> // for std::isspace
 #ifdef GLOG_OS_WINDOWS
 #include "windows/dirent.h"
 #else