--- a/scripts/general/prepad.m
+++ b/scripts/general/prepad.m
@@ -46,7 +46,7 @@
     c = 0;
   else
     if (! isscalar (c))
-      error ("prepad: third argument must be empty or a scalar");
+      error ("prepad: pad value C must be empty or a scalar");
     endif
   endif
 
@@ -63,7 +63,7 @@
   endif
 
   if (! isscalar (l) || l < 0)
-    error ("prepad: second argument must be a positive scaler");
+    error ("prepad: length L must be a positive scalar");
   endif
 
   if (dim > nd)
@@ -97,5 +97,10 @@
 %!error prepad ()
 %!error prepad (1)
 %!error prepad (1,2,3,4,5)
-%!error prepad ([1,2], 2, 2,3)
+%!error <C must be empty or a scalar> prepad ([1,2], 2, ones (2))
+%!error <DIM must be an integer> prepad ([1,2], 2, 2, ones (3))
+%!error <DIM must be an integer> prepad ([1,2], 2, 2, 1.1)
+%!error <DIM must be an integer> prepad ([1,2], 2, 2, 3)
+%!error <L must be a positive scalar> prepad ([1,2], ones (2))
+%!error <L must be a positive scalar> prepad ([1,2], -1)