diff --git a/src/main/test-mr.sh b/src/main/test-mr.sh
index 9c625f3..1cf739a 100644
--- a/src/main/test-mr.sh
+++ b/src/main/test-mr.sh
@@ -1,15 +1,22 @@
 #!/usr/bin/env bash
 
 #
-# basic map-reduce test
+# map-reduce tests
 #
 
-RACE=
+# comment this out to run the tests without the Go race detector.
+RACE=-race
 
-if [ "$OSTYPE" != "darwin" ]
+if [ "$OSTYPE" = "darwin" ]
 then
-  # comment this out to run the tests without the Go race detector.
-  RACE=-race
+  if go version | grep 'go1.17.[012345]'
+  then
+    # -race with plug-ins on x86 MacOS 12 with
+    # go1.17 before 1.17.6 sometimes crash.
+    RACE=
+    echo '*** Turning off -race since it may not work on a Mac'
+    echo '    with ' `go version`
+  fi
 fi
 
 # run the test in a fresh sub-directory.