diff --git a/src/cas/generic/st/casStreamOS.cc b/src/cas/generic/st/casStreamOS.cc
index 1bb27308b..2775cbdf7 100644
--- a/src/cas/generic/st/casStreamOS.cc
+++ b/src/cas/generic/st/casStreamOS.cc
@@ -170,7 +170,7 @@ epicsTimerNotify::expireStatus casStreamEvWakeup::expire ( const epicsTime & /*
 //
 // casStreamEvWakeup::start()
 //
-void casStreamEvWakeup::start( casStreamOS &os )
+void casStreamEvWakeup::start( casStreamOS & )
 {    
     // care is needed here because this is called
     // asynchronously by postEvent
diff --git a/src/cas/io/bsdSocket/casDGIntfIO.cc b/src/cas/io/bsdSocket/casDGIntfIO.cc
index 9fb2b07d3..dc53a4c30 100644
--- a/src/cas/io/bsdSocket/casDGIntfIO.cc
+++ b/src/cas/io/bsdSocket/casDGIntfIO.cc
@@ -293,7 +293,8 @@ void casDGIntfIO::xSetNonBlocking()
 
     if ( this->bcastRecvSock != INVALID_SOCKET ) {
         yes = true;
-        int status = socket_ioctl ( this->bcastRecvSock, FIONBIO, &yes ); // X aCC 392
+        int status = socket_ioctl ( this->bcastRecvSock, // X aCC 392
+                                    FIONBIO, &yes );
         if ( status < 0 ) {
             char sockErrBuf[64];
             epicsSocketConvertErrnoToString ( sockErrBuf, sizeof ( sockErrBuf ) );
diff --git a/src/libCom/test/epicsMaxThreadsMain.cpp b/src/libCom/test/epicsMaxThreadsMain.cpp
index 85c06d43b..89fd0d202 100644
--- a/src/libCom/test/epicsMaxThreadsMain.cpp
+++ b/src/libCom/test/epicsMaxThreadsMain.cpp
@@ -21,7 +21,7 @@
 extern "C" void epicsMaxThreads(void);
 
 
-int main(int argc,char *argv[])
+int main(int /*argc*/, char * /*argv[]*/ )
 {
     epicsMaxThreads();
     printf("main terminating\n");
diff --git a/src/libCom/test/epicsOkToBlockTestMain.cpp b/src/libCom/test/epicsOkToBlockTestMain.cpp
index 57962cbab..c9105f8c5 100644
--- a/src/libCom/test/epicsOkToBlockTestMain.cpp
+++ b/src/libCom/test/epicsOkToBlockTestMain.cpp
@@ -21,7 +21,7 @@
 extern "C" void epicsOkToBlockTest(void);
 
 
-int main(int argc,char *argv[])
+int main(int /*argc*/, char * /*argv[]*/ )
 {
     epicsOkToBlockTest();
     printf("main terminating\n");