diff --git a/src/include/os/vxWorks/osiSock.h b/src/include/os/vxWorks/osiSock.h
index c573e6c30..7e9eabf0f 100644
--- a/src/include/os/vxWorks/osiSock.h
+++ b/src/include/os/vxWorks/osiSock.h
@@ -19,6 +19,7 @@ extern "C" {
 #include <netinet/in.h>
 #include <netinet/tcp.h>
 #include <arpa/inet.h>
+#include <net/if.h>
 
 void ipAddrToA (const struct sockaddr_in *pInetAddr, 
 			char *pBuf, const unsigned bufSize);
diff --git a/src/libCom/osi/os/vxWorks/osdSock.h b/src/libCom/osi/os/vxWorks/osdSock.h
index c573e6c30..7e9eabf0f 100644
--- a/src/libCom/osi/os/vxWorks/osdSock.h
+++ b/src/libCom/osi/os/vxWorks/osdSock.h
@@ -19,6 +19,7 @@ extern "C" {
 #include <netinet/in.h>
 #include <netinet/tcp.h>
 #include <arpa/inet.h>
+#include <net/if.h>
 
 void ipAddrToA (const struct sockaddr_in *pInetAddr, 
 			char *pBuf, const unsigned bufSize);