diff --git a/gdb/testsuite/ChangeLog b/gdb/testsuite/ChangeLog
index 5bbcb2f420..9addcbb9e9 100644
--- a/gdb/testsuite/ChangeLog
+++ b/gdb/testsuite/ChangeLog
@@ -1,3 +1,7 @@
+2018-05-02  Tom Tromey  <tom@tromey.com>
+
+	* gdb.python/py-parameter.exp: Set test message.
+
 2018-05-02  Tom Tromey  <tom@tromey.com>
 
 	PR python/20084:
diff --git a/gdb/testsuite/gdb.python/py-parameter.exp b/gdb/testsuite/gdb.python/py-parameter.exp
index b9ff9f1ec0..1ea79b8946 100644
--- a/gdb/testsuite/gdb.python/py-parameter.exp
+++ b/gdb/testsuite/gdb.python/py-parameter.exp
@@ -197,7 +197,8 @@ foreach kind {PARAM_ZUINTEGER PARAM_ZUINTEGER_UNLIMITED} {
     if {$kind == "PARAM_ZUINTEGER"} {
 	gdb_test "python test_param_$kind.value = -1" "RuntimeError: Range exceeded.*"
     } else {
-	gdb_test_no_output "python test_param_$kind.value = -1" ""
+	gdb_test_no_output "python test_param_$kind.value = -1" \
+	    "check that PARAM_ZUINTEGER value can be set to -1"
 	gdb_test "python print(gdb.parameter('test-$kind'))" "-1" \
 	    "check that PARAM_ZUINTEGER value is -1 after setting"
     }