diff --git a/src/libutil/archive.cc b/src/libutil/archive.cc
index bef0f4d578..5450fd2f71 100644
--- a/src/libutil/archive.cc
+++ b/src/libutil/archive.cc
@@ -7,9 +7,7 @@
 #include <vector>
 #include <map>
 
-#define _DARWIN_C_SOURCE // hack to get strcasecmp on old Darwin versions
-#include <cstring>
-#undef _DARWIN_C_SOURCE
+#include <strings.h> // for strcasecmp
 
 #include <sys/types.h>
 #include <sys/stat.h>