--- a/inst/@galois/deconv.m
+++ b/inst/@galois/deconv.m
@@ -77,3 +77,7 @@
   endif
 
 endfunction
+
+%%Test input validation
+%!error deconv (gf (1, 2), gf (1, 3))
+%!error deconv (gf (eye (3), 3), gf (eye (3), 3))