diff --git a/src/libCom/test/epicsEventTestMain.cpp b/src/libCom/test/epicsEventTestMain.cpp
index 4586abdbf..fd7c0cfec 100644
--- a/src/libCom/test/epicsEventTestMain.cpp
+++ b/src/libCom/test/epicsEventTestMain.cpp
@@ -25,7 +25,7 @@ extern "C" void epicsEventTest(int nthreads,int errVerbose);
 int main(int argc,char *argv[])
 {
     int nthreads = 2;
-    int errVerbose = 0;
+    int errVerboseIn = 0;
 
     if(argc>1) {
         if(isdigit(*argv[1])) {
@@ -37,13 +37,13 @@ int main(int argc,char *argv[])
     }
     if(argc>2) {
         if(isdigit(*argv[2])) {
-            sscanf(argv[2],"%d",&errVerbose);
-            printf("errVerbose %d\n",errVerbose);
+            sscanf(argv[2],"%d",&errVerboseIn);
+            printf("errVerbose %d\n",errVerboseIn);
         } else {
             printf("Illegal argument %s\n",argv[1]);
         }
     }
-    epicsEventTest(nthreads,errVerbose);
+    epicsEventTest(nthreads,errVerboseIn);
     printf("main terminating\n");
     return(0);
 }
diff --git a/src/libCom/test/epicsMessageQueueTest.cpp b/src/libCom/test/epicsMessageQueueTest.cpp
index 899797867..0cb20af56 100644
--- a/src/libCom/test/epicsMessageQueueTest.cpp
+++ b/src/libCom/test/epicsMessageQueueTest.cpp
@@ -41,7 +41,7 @@ randBelow(int n)
     return (int)((double)n*rand()/(RAND_MAX+1.0));
 }
 
-static void
+extern "C" void
 receiver0(void *arg)
 {
     epicsMessageQueue *q = (epicsMessageQueue *)arg;
@@ -52,7 +52,7 @@ receiver0(void *arg)
     delete q;
 }
 
-static void
+extern "C" void
 receiver(void *arg)
 {
     epicsMessageQueue *q = (epicsMessageQueue *)arg;
@@ -84,7 +84,7 @@ receiver(void *arg)
     }
 }
 
-static void
+extern "C" void
 sender(void *arg)
 {
     epicsMessageQueue *q = (epicsMessageQueue *)arg;
diff --git a/src/libCom/test/epicsMutexTest.cpp b/src/libCom/test/epicsMutexTest.cpp
index e66c1d967..9a29b34d1 100644
--- a/src/libCom/test/epicsMutexTest.cpp
+++ b/src/libCom/test/epicsMutexTest.cpp
@@ -28,14 +28,13 @@
 #include "epicsEvent.h"
 #include "errlog.h"
 
-
 typedef struct info {
     int        threadnum;
     epicsMutexId mutex;
     int        quit;
 }info;
 
-static void mutexThread ( void * arg )
+extern "C" void mutexThread ( void * arg )
 {
     info *pinfo = (info *)arg;
     time_t tp;
@@ -212,7 +211,7 @@ struct verifyTryLock {
     epicsEventId done;
 };
 
-static void verifyTryLockThread ( void *pArg )
+extern "C" void verifyTryLockThread ( void *pArg )
 {
     struct verifyTryLock *pVerify = 
         ( struct verifyTryLock * ) pArg;
diff --git a/src/libCom/test/epicsMutexTestMain.cpp b/src/libCom/test/epicsMutexTestMain.cpp
index a8df3b74f..f68a995da 100644
--- a/src/libCom/test/epicsMutexTestMain.cpp
+++ b/src/libCom/test/epicsMutexTestMain.cpp
@@ -25,7 +25,7 @@ extern "C" void epicsMutexTest(int nthreads,int errVerbose);
 int main(int argc,char *argv[])
 {
     int nthreads = 2;
-    int errVerbose = 0;
+    int errVerboseIn = 0;
 
     if(argc>1) {
         if(isdigit(*argv[1])) {
@@ -37,13 +37,13 @@ int main(int argc,char *argv[])
     }
     if(argc>2) {
         if(isdigit(*argv[2])) {
-            sscanf(argv[2],"%d",&errVerbose);
-            printf("errVerbose %d\n",errVerbose);
+            sscanf(argv[2],"%d",&errVerboseIn);
+            printf("errVerbose %d\n",errVerboseIn);
         } else {
             printf("Illegal argument %s\n",argv[1]);
         }
     }
-    epicsMutexTest(nthreads,errVerbose);
+    epicsMutexTest(nthreads,errVerboseIn);
     printf("main terminating\n");
     return(0);
 }
diff --git a/src/libCom/test/epicsThreadPrivateTest.cpp b/src/libCom/test/epicsThreadPrivateTest.cpp
index a737cbe3c..5b468a92b 100644
--- a/src/libCom/test/epicsThreadPrivateTest.cpp
+++ b/src/libCom/test/epicsThreadPrivateTest.cpp
@@ -20,7 +20,7 @@ static epicsThreadPrivate < bool > priv;
 
 static bool doneFlag = false;
 
-void epicsThreadPrivateTestThread ( void * )
+extern "C" void epicsThreadPrivateTestThread ( void * )
 {
     assert ( 0 == priv.get () );
     static bool var;
diff --git a/src/libCom/test/epicsThreadTestMain.cpp b/src/libCom/test/epicsThreadTestMain.cpp
index e553bb418..122d81684 100644
--- a/src/libCom/test/epicsThreadTestMain.cpp
+++ b/src/libCom/test/epicsThreadTestMain.cpp
@@ -24,7 +24,7 @@ extern "C" void threadTest(int nthreads,int errVerbose);
 int main(int argc,char *argv[])
 {
     int nthreads = 2;
-    int errVerbose = 0;
+    int errVerboseIn = 0;
 
     if(argc>1) {
         if(isdigit(*argv[1])) {
@@ -36,13 +36,13 @@ int main(int argc,char *argv[])
     }
     if(argc>2) {
         if(isdigit(*argv[2])) {
-            sscanf(argv[2],"%d",&errVerbose);
-            printf("errVerbose %d\n",errVerbose);
+            sscanf(argv[2],"%d",&errVerboseIn);
+            printf("errVerbose %d\n",errVerboseIn);
         } else {
             printf("Illegal argument %s\n",argv[1]);
         }
     }
-    if(nthreads>0) threadTest(nthreads,errVerbose);
+    if(nthreads>0) threadTest(nthreads,errVerboseIn);
     printf("main terminating\n");
     return(0);
 }