diff --git a/src/libCom/test/blockingSockTest.cpp b/src/libCom/test/blockingSockTest.cpp
index 55471c58a..cdc63a0c9 100644
--- a/src/libCom/test/blockingSockTest.cpp
+++ b/src/libCom/test/blockingSockTest.cpp
@@ -1,6 +1,7 @@
 
 #include <string.h>
 #include <assert.h>
+#include <stdio.h>
 
 #include "osiSock.h"
 #include "osiWireFormat.h"
diff --git a/src/libCom/test/epicsThreadPrivateTest.cpp b/src/libCom/test/epicsThreadPrivateTest.cpp
index 5442b041c..cf1f43c1b 100644
--- a/src/libCom/test/epicsThreadPrivateTest.cpp
+++ b/src/libCom/test/epicsThreadPrivateTest.cpp
@@ -11,6 +11,7 @@
 
 /* Author: Jeff Hill Date:    March 28 2001 */
 
+#include <stdio.h>
 
 #include "epicsTime.h"
 #include "epicsThread.h"
diff --git a/src/libCom/test/epicsTimerTest.cpp b/src/libCom/test/epicsTimerTest.cpp
index 12ebb5308..02e359257 100644
--- a/src/libCom/test/epicsTimerTest.cpp
+++ b/src/libCom/test/epicsTimerTest.cpp
@@ -16,6 +16,8 @@
  */
 
 #include <math.h>
+#include <stdio.h>
+#include <stdlib.h>
 
 #include "epicsTimer.h"
 #include "epicsEvent.h"