diff --git a/CHANGELOG.md b/CHANGELOG.md
index 54c8a2d..d66368d 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -2,6 +2,10 @@
 
 ## Unreleased
 
+- Fixed a bug where an authentication error would result in a failure with a
+  confusing error message.
+  ([Giacomo Cavalieri](https://github.com/giacomocavalieri))
+
 - Added support for the `timestamp` type, represented as tuples
   `#(#(Int, Int, Int), #(Int Int Int))` with
   `#(#(year, month, day), #(hour, minute, second))`.
diff --git a/src/squirrel/internal/database/postgres_protocol.gleam b/src/squirrel/internal/database/postgres_protocol.gleam
index 20fbe46..922c35b 100644
--- a/src/squirrel/internal/database/postgres_protocol.gleam
+++ b/src/squirrel/internal/database/postgres_protocol.gleam
@@ -1370,7 +1370,16 @@ fn decode_fields_rec(binary, result) {
           case bit_array.to_string(head) {
             Ok(value) ->
               decode_fields_rec(tail, [#(field_type, value), ..result])
-            Error(Nil) -> dec_err("invalid field encoding", binary)
+            Error(Nil) ->
+              // Sometimes Postgres can reply with a string that is not utf8
+              // encoded, in that case we try our best to still get something
+              // out of it.
+              // If all fails, we still return an error.
+              case recover_string(head) {
+                Ok(value) ->
+                  decode_fields_rec(tail, [#(field_type, value), ..result])
+                Error(Nil) -> dec_err("invalid field encoding", binary)
+              }
           }
         }
         _ -> dec_err("invalid field separator", binary)
@@ -1380,6 +1389,9 @@ fn decode_fields_rec(binary, result) {
   }
 }
 
+@external(erlang, "squirrel_ffi", "recover_string")
+fn recover_string(value: a) -> Result(String, Nil)
+
 type BinarySplitOption {
   Global
 }
diff --git a/src/squirrel_ffi.erl b/src/squirrel_ffi.erl
index 5fdf79f..5fd25f0 100644
--- a/src/squirrel_ffi.erl
+++ b/src/squirrel_ffi.erl
@@ -1,5 +1,13 @@
 -module(squirrel_ffi).
--export([unique/0, exit/1]).
+-export([unique/0, exit/1, recover_string/1]).
+
+recover_string(Binary) ->
+    try
+        Chars = lists:flatten(io_lib:format("~ts", [Binary])),
+        {ok, unicode:characters_to_binary(Chars)}
+    catch
+        _ -> {error, nil}
+    end.
 
 unique() ->
     erlang:unique_integer([positive]).