diff --git a/test/basetest/testing.py b/test/basetest/testing.py
index e7e7e98b2..66ad529bc 100644
--- a/test/basetest/testing.py
+++ b/test/basetest/testing.py
@@ -7,11 +7,11 @@ from .taskd import Taskd
 
 
 class BaseTestCase(unittest.TestCase):
-    def diag(self, out):
-        sys.stderr.write("--- diag start ---\n")
+    def tap(self, out):
+        sys.stderr.write("--- tap output start ---\n")
         for line in out.splitlines():
             sys.stderr.write(line + '\n')
-        sys.stderr.write("---  diag end  ---\n")
+        sys.stderr.write("---  tap output end  ---\n")
 
 
 @unittest.skipIf(TASKW_SKIP, "TASKW_SKIP set, skipping task tests.")
diff --git a/test/bug.360.t b/test/bug.360.t
index 555439a86..ec0e54e36 100755
--- a/test/bug.360.t
+++ b/test/bug.360.t
@@ -119,8 +119,7 @@ class TestBug360AllowedChanges(BaseTestBug360):
         self.assertNotIn(expected, err)
 
         # Make sure no duplicate tasks were created
-        args = ("diag",)
-        code, out, err = self.t(args)
+        code, out, err = self.t.diag()
         expected = "No duplicates found"
         self.assertIn(expected, out)
 
diff --git a/test/diag.t b/test/diag.t
index 0d0e52206..0783bd5b7 100755
--- a/test/diag.t
+++ b/test/diag.t
@@ -42,7 +42,7 @@ class TestDiagColor(TestCase):
     def test_diag_color_builtin(self):
         """Task diag output, so we can monitor platforms"""
         code, out, err = self.t.diag()
-        self.diag (out)
+        self.tap(out)
 
 
 if __name__ == "__main__":
diff --git a/test/template.t b/test/template.t
index 8679f93f5..65967a3ca 100644
--- a/test/template.t
+++ b/test/template.t
@@ -60,7 +60,7 @@ class TestBugNumber(TestCase):
         self.assertRegexpMatches(out, expected)
 
         # TAP diagnostics on the bas
-        self.diag("Yay TAP diagnostics")
+        self.tap("Yay TAP diagnostics")
 
     def test_faketime(self):
         """Running tests using libfaketime"""
diff --git a/test/version.t b/test/version.t
index 3e8ade868..a757a1414 100755
--- a/test/version.t
+++ b/test/version.t
@@ -106,9 +106,7 @@ class TestVersion(TestCase):
         """Task binary matches the current git commit"""
         expected = "Commit: {0}".format(self.slurp_git())
 
-        args = ("diag",)
-
-        code, out, err = self.t(args)
+        code, out, err = self.t.diag()
         self.assertIn(expected, out)