diff --git a/src/libCom/test/cvtFastTest.c b/src/libCom/test/cvtFastTest.c
index 7943f5baf..ac853ecc3 100644
--- a/src/libCom/test/cvtFastTest.c
+++ b/src/libCom/test/cvtFastTest.c
@@ -13,6 +13,7 @@
 
 #include <math.h>
 #include <float.h>
+#include <stdio.h>
 
 #include "epicsUnitTest.h"
 #include "cvtFast.h"