diff --git a/Gt/Core.hs b/Gt/Core.hs
--- a/Gt/Core.hs
+++ b/Gt/Core.hs
@@ -19,7 +19,7 @@
     return $ show $ jresp_to_resp jresp
 
 do_trans_each_word :: IO String
-do_trans_each_word = undefined
+do_trans_each_word = error "Gt.Core.do_trans_each_word: unimplemented"
 
 jresp_to_resp :: String -> Resp
 jresp_to_resp jobj = foldr fill_resp br obj_list
@@ -37,7 +37,7 @@
 -- Sentences processing
 jval_to_sentences :: JSValue -> Sentences
 jval_to_sentences (JSArray jval) = Sentences { sent_list = foldr jsso_to_sentence [] jval }
-jval_to_sentences _              = undefined
+jval_to_sentences _              = error "Gt.Core.jval_to_sentences: not a JSArray"
 
 jsso_to_sentence :: JSValue -> [Sentence] -> [Sentence]
 jsso_to_sentence (JSObject jobj) acc =
@@ -46,7 +46,7 @@
     -- so just leaving as is
     foldr tot (Sentence "" "" "") in_list:acc
     where in_list = fromJSObject jobj
-jsso_to_sentence _ _ = undefined
+jsso_to_sentence _ _ = error "Gt.Core.jsso_to_sentence: not a JSObject"
 
 -- Conversion of inner list with trans-orig-translit data
 tot :: (String, JSValue) -> Sentence -> Sentence
@@ -60,7 +60,7 @@
 -- Dictionaries processing
 jval_to_dicts :: JSValue -> Dicts
 jval_to_dicts (JSArray jval) = Dicts { dict_list = foldr jsdo_to_dict [] jval }
-jval_to_dicts _ = undefined
+jval_to_dicts _ = error "Gt.Core.jval_to_dicts: not a JSArray"
 
 jsdo_to_dict :: JSValue -> [Dict] -> [Dict]
 jsdo_to_dict (JSObject jobj) acc =
@@ -69,7 +69,7 @@
     -- so just leaving as is
     foldr pt (Dict "" []) in_list:acc
     where in_list = fromJSObject jobj
-jsdo_to_dict _ _ = undefined
+jsdo_to_dict _ _ = error "Gt.Core.jsdo_to_dict: not a JSObject"
 
 -- Conversion of inner list with pos-term data
 pt :: (String, JSValue) -> Dict -> Dict
diff --git a/Gt/Helpers.hs b/Gt/Helpers.hs
--- a/Gt/Helpers.hs
+++ b/Gt/Helpers.hs
@@ -39,7 +39,7 @@
 -- JSON deconstruct helpers
 from_ok :: Result a -> a
 from_ok (Ok x)    = x
-from_ok (Error _) = undefined
+from_ok (Error e) = error $ "Gt.Helpers.from_ok: " ++ show e
 
 jarr_to_list :: JSValue -> [JSValue]
 jarr_to_list (JSArray jarr) = jarr
@@ -51,4 +51,4 @@
 
 jlist_to_slist :: JSValue -> [String]
 jlist_to_slist (JSArray xs) = map jstr_to_str xs
-jlist_to_slist _            = undefined
+jlist_to_slist _            = error "Gt.Helpers.jlist_to_slist: not a JSArray"
diff --git a/Gt/Net.hs b/Gt/Net.hs
--- a/Gt/Net.hs
+++ b/Gt/Net.hs
@@ -16,7 +16,7 @@
 trans_url :: Lang -> Lang -> String -> String
 trans_url sl tl text =
     exportURL $ foldl add_param base_url [("text", text), ("sl", sl), ("tl", tl)]
-        where base_url = fromJust $ importURL "http://translate.google.com/translate_a/t?client=t&pc=0&oc=1&hl=en&ie=UTF-8&oe=UTF-8"
+        where base_url = fromJust $ importURL "http://translate.google.com/translate_a/t?client=j&pc=0&oc=1&hl=en&ie=UTF-8&oe=UTF-8"
 
 get_resp :: Lang -> Lang -> String -> IO String
 get_resp sl tl str =
@@ -24,4 +24,4 @@
      return $ decodeString result
 
 get_resp_each_word :: Lang -> Lang -> String -> IO String
-get_resp_each_word = undefined
+get_resp_each_word = error "Gt.Net.get_resp_each_word: undefined"
diff --git a/gt-tools.cabal b/gt-tools.cabal
--- a/gt-tools.cabal
+++ b/gt-tools.cabal
@@ -1,5 +1,5 @@
 name:                   gt-tools
-version:                0.1.4
+version:                0.1.4.1
 cabal-version:          >= 1.8
 build-type:             Simple
 license:                GPL