diff --git a/toolbox/is.m b/toolbox/is.m
index 4fcc0b8..b1c9292 100644
--- a/toolbox/is.m
+++ b/toolbox/is.m
@@ -3,5 +3,9 @@ function is(a, b, comment)
 %% tests that the two values a and b are equal. Calls ok() to handle
 %% the test output logic, so has all the same capabilities as that
 %% function.
-    ok(a == b, comment);
-endfunction
\ No newline at end of file
+    if nargin == 2
+        ok(a == b, comment);
+    else
+        ok(a == b);
+    endif
+endfunction
diff --git a/toolbox/nok.m b/toolbox/nok.m
index 10c7f14..0fa14f4 100644
--- a/toolbox/nok.m
+++ b/toolbox/nok.m
@@ -9,5 +9,10 @@ function nok(bad, comment)
     else
         bad = 0;
     end
-    ok(bad, comment);
+    
+    if nargin == 2
+        ok(bad, comment);
+    else
+        ok(bad);
+    endif
 endfunction
diff --git a/toolbox/ok.m b/toolbox/ok.m
index 4c945a2..896ade0 100644
--- a/toolbox/ok.m
+++ b/toolbox/ok.m
@@ -8,9 +8,12 @@ function ok(good, comment)
     global _TAP_TEST_CNT;   % the number of the current test
 
     if good == 0
-        printf("not ok %d %s", _TAP_TEST_CNT, comment);
-    else
-        printf("ok %d %s", _TAP_TEST_CNT, comment);
+	printf("not ");
+    end
+    printf("ok %d", _TAP_TEST_CNT);
+
+    if nargin == 2
+        printf(" %s", comment);
     end
 
     if _TAP_TODO == 1