diff --git a/src/libCom/Makefile b/src/libCom/Makefile
index 5d33ea7ee..cc2924fe0 100644
--- a/src/libCom/Makefile
+++ b/src/libCom/Makefile
@@ -175,6 +175,8 @@ SRCS += epicsMessageQueue.cpp
 
 SRCS += osdSock.c
 SRCS += osiSock.c
+SRCS += systemCallIntMech.cpp
+SRCS += epicsSocketConvertErrnoToString.cpp
 SRCS += osdAssert.c
 SRCS += osdFindSymbol.c
 SRCS += osdInterrupt.c