diff --git a/src/rio/turtle/mod.rs b/src/rio/turtle/mod.rs
index fe1fd4eb..742b6809 100644
--- a/src/rio/turtle/mod.rs
+++ b/src/rio/turtle/mod.rs
@@ -44,10 +44,8 @@ mod grammar {
         let mut string_buffer = String::default();
         BufReader::new(source).read_to_string(&mut string_buffer)?;
 
-        match turtleDoc(&string_buffer, &mut state, &mut triple_buffer) {
-            Ok(_) => Ok(triple_buffer.into_iter()),
-            Err(error) => Err(error.into()),
-        }
+        turtleDoc(&string_buffer, &mut state, &mut triple_buffer)?;
+        Ok(triple_buffer.into_iter())
     }
 }
 
diff --git a/src/sparql/parser.rs b/src/sparql/parser.rs
index b3bdb922..79ebd972 100644
--- a/src/sparql/parser.rs
+++ b/src/sparql/parser.rs
@@ -298,13 +298,10 @@ mod grammar {
         let mut string_buffer = String::default();
         BufReader::new(source).read_to_string(&mut string_buffer)?;
 
-        match QueryUnit(
+        Ok(QueryUnit(
             &unescape_unicode_codepoints(Cow::from(string_buffer)),
             &mut state,
-        ) {
-            Ok(query) => Ok(query),
-            Err(error) => Err(error.into()),
-        }
+        )?)
     }
 }
 
diff --git a/src/sparql/sparql_grammar.rustpeg b/src/sparql/sparql_grammar.rustpeg
index 29c939b1..1c6091b6 100644
--- a/src/sparql/sparql_grammar.rustpeg
+++ b/src/sparql/sparql_grammar.rustpeg
@@ -1074,7 +1074,7 @@ PERCENT -> () = "%" HEX HEX
 HEX -> () = ([0-9A-Fa-f])
 
 //[173]
-PN_LOCAL_ESC -> char = "\\" c:$([_~\.\-!$&'()*+,;=/?#@%:]) { c.chars().next().unwrap() } //TODO: added '/' to make tests pass but is it valid?
+PN_LOCAL_ESC -> char = "\\" c:$([_~\.\-!$&'()*+,;=/?#@%]) { c.chars().next().unwrap() } //TODO: added '/' to make tests pass but is it valid?
 
 //space
 _ = #quiet<([ \t\n\r] / comment)*>
diff --git a/tests/rdf_test_cases.rs b/tests/rdf_test_cases.rs
index bc402bf0..a2c88062 100644
--- a/tests/rdf_test_cases.rs
+++ b/tests/rdf_test_cases.rs
@@ -157,11 +157,9 @@ fn sparql_w3c_syntax_testsuite() {
             }
         } else if test.kind == "NegativeSyntaxTest11" {
             //TODO
-            /*assert!(
-                client.load_sparql_query(test.action.clone()).is_err(),
-                "Failure on {}",
-                test
-            );*/
+            if let Ok(result) = client.load_sparql_query(test.action.clone()) {
+                eprintln!("Failure on {}. The output tree is: {}", test, result);
+            }
         } else {
             assert!(false, "Not supported test: {}", test);
         }