diff --git a/panda/src/express/multifile.cxx b/panda/src/express/multifile.cxx
index 210ccf9519..02d2a48078 100644
--- a/panda/src/express/multifile.cxx
+++ b/panda/src/express/multifile.cxx
@@ -23,6 +23,7 @@
 #include "virtualFileSystem.h"
 
 #include <algorithm>
+#include <time.h>
 
 // This sequence of bytes begins each Multifile to identify it as a
 // Multifile.