diff --git a/src/ca/cadef.h b/src/ca/cadef.h
index 3988be7f8..4d3be961e 100644
--- a/src/ca/cadef.h
+++ b/src/ca/cadef.h
@@ -676,7 +676,7 @@ epicsShareFunc void epicsShareAPI ca_signal_formated (long ca_status, const char
  */
 epicsShareFunc const char * epicsShareAPI ca_host_name (chid channel);
 /* thread safe version */
-epicsShareFunc void epicsShareAPI ca_get_host_name ( chid pChan, 
+epicsShareFunc unsigned epicsShareAPI ca_get_host_name ( chid pChan, 
     char *pBuf, unsigned bufLength );
 
 /*