diff --git a/src/libCom/test/epicsAlgorithmTest.cpp b/src/libCom/test/epicsAlgorithmTest.cpp
index 8e14b0191..2d3957dd8 100644
--- a/src/libCom/test/epicsAlgorithmTest.cpp
+++ b/src/libCom/test/epicsAlgorithmTest.cpp
@@ -15,8 +15,9 @@
 
 #include "epicsAlgorithm.h"
 
-#ifdef vxWorks
+#if defined(vxWorks) || defined(__rtems__)
   #define MAIN epicsAlgorithm
+  extern "C" int MAIN(int /*argc*/, char* /*argv[]*/);
 #else
   #define MAIN main
 #endif
diff --git a/src/libCom/test/epicsListTest.cpp b/src/libCom/test/epicsListTest.cpp
index 688cbf98c..babd932e2 100644
--- a/src/libCom/test/epicsListTest.cpp
+++ b/src/libCom/test/epicsListTest.cpp
@@ -21,8 +21,9 @@
 using std::cout;
 using std::endl;
 
-#ifdef vxWorks
+#if defined(vxWorks) || defined(__rtems__)
   #define MAIN epicsListTest
+  extern "C" int MAIN(int /*argc*/, char* /*argv[]*/);
 #else
   #define MAIN main
 #endif