diff --git a/test/search_test2.cpp b/test/search_test2.cpp
index 4631105..4d772ca 100755
--- a/test/search_test2.cpp
+++ b/test/search_test2.cpp
@@ -14,6 +14,7 @@
 #define BOOST_TEST_MAIN
 #include <boost/test/unit_test.hpp>
 
+#include <ctime>        // for clock_t
 #include <iostream>
 #include <fstream>
 #include <iomanip>
diff --git a/test/search_test3.cpp b/test/search_test3.cpp
index ee32f6a..96226cd 100755
--- a/test/search_test3.cpp
+++ b/test/search_test3.cpp
@@ -14,6 +14,7 @@
 #define BOOST_TEST_MAIN
 #include <boost/test/unit_test.hpp>
 
+#include <ctime>        // for clock_t
 #include <iostream>
 #include <fstream>
 #include <iomanip>