diff --git a/src/ca/hostNameCache.cpp b/src/ca/hostNameCache.cpp
index ee9bde5ef..ba8c883ce 100644
--- a/src/ca/hostNameCache.cpp
+++ b/src/ca/hostNameCache.cpp
@@ -16,6 +16,8 @@
 
 #define epicsAssertAuthor "Jeff Hill johill@lanl.gov"
 
+#include <string.h>
+
 #include "iocinf.h"
 #include "hostNameCache.h"