diff --git a/fine/build.rs b/fine/build.rs
index f9f82d57..80b3db35 100644
--- a/fine/build.rs
+++ b/fine/build.rs
@@ -82,6 +82,8 @@ fn generate_test_for_file(path: PathBuf) -> String {
             assertions.push(quote! {
                 crate::assert_no_errors(&_tree, &_lines);
             });
+        } else if line.starts_with("@") {
+            panic!("Test file {display_path} has unknown directive: {line}");
         }
     }
 
diff --git a/fine/tests/expression/argument.fine b/fine/tests/expression/argument.fine
index e4d5bdd1..c927f7cd 100644
--- a/fine/tests/expression/argument.fine
+++ b/fine/tests/expression/argument.fine
@@ -2,6 +2,7 @@ fun foo(x: f64) {
   x + 7
 }
 
+// @no-errors
 // @type: 20 f64
 // @concrete:
 // | File
diff --git a/fine/tests/expression/arithmetic.fine b/fine/tests/expression/arithmetic.fine
index ba1912a8..9dfa9dd0 100644
--- a/fine/tests/expression/arithmetic.fine
+++ b/fine/tests/expression/arithmetic.fine
@@ -1,5 +1,6 @@
 1 * 2 + -3 * 4;
 
+// @no-errors
 // @type: 6 f64
 // @concrete:
 // | File
diff --git a/fine/tests/expression/block.fine b/fine/tests/expression/block.fine
index 524514bc..20fd57a6 100644
--- a/fine/tests/expression/block.fine
+++ b/fine/tests/expression/block.fine
@@ -1,10 +1,10 @@
+{}
+
+// @no-errors
+// @type: 0 ()
 // @concrete:
 // | File
 // |   Block
 // |     LeftBrace:'"{"'
 // |     RightBrace:'"}"'
 // |
-
-{}
-
-// @type: 94 ()
diff --git a/fine/tests/expression/boolean.fine b/fine/tests/expression/boolean.fine
index e3405c51..abf299d4 100644
--- a/fine/tests/expression/boolean.fine
+++ b/fine/tests/expression/boolean.fine
@@ -1,3 +1,7 @@
+true and false or false and !true;
+
+// @no-errors
+// @type: 15 bool
 // @concrete:
 // | File
 // |   ExpressionStatement
@@ -18,7 +22,3 @@
 // |           LiteralExpression
 // |             True:'"true"'
 // |     Semicolon:'";"'
-//
-true and false or false and !true;
-
-// @type: 549 bool
diff --git a/fine/tests/expression/conditional.fine b/fine/tests/expression/conditional.fine
index c5383036..dd5baf92 100644
--- a/fine/tests/expression/conditional.fine
+++ b/fine/tests/expression/conditional.fine
@@ -1,3 +1,24 @@
+if true { "discarded"; 23 } else { 45 }
+
+// @no-errors
+// Here come some type probes!
+// (type of the condition)
+// @type: 3 bool
+//
+// (the discarded expression)
+// @type: 10 string
+//
+// (the "then" clause)
+// @type: 23 f64
+// @type: 26 f64
+//
+// (the "else" clause)
+// @type: 35 f64
+// @type: 38 f64
+//
+// (the overall expression)
+// @type: 0 f64
+//
 // @concrete:
 // | File
 // |   IfStatement
@@ -23,22 +44,3 @@
 // |             Number:'"45"'
 // |         RightBrace:'"}"'
 //
-if true { "discarded"; 23 } else { 45 }
-
-// Here come some type probes!
-// (type of the condition)
-// @type: 667 bool
-//
-// (the discarded expression)
-// @type: 674 string
-//
-// (the "then" clause)
-// @type: 686 f64
-// @type: 689 f64
-//
-// (the "else" clause)
-// @type: 696 f64
-// @type: 699 f64
-//
-// (the overall expression)
-// @type: 664 f64
\ No newline at end of file
diff --git a/fine/tests/expression/number.fine b/fine/tests/expression/number.fine
index 4995ea31..3b5411f6 100644
--- a/fine/tests/expression/number.fine
+++ b/fine/tests/expression/number.fine
@@ -1,10 +1,10 @@
+42;
+
+// @no-errors
+// @type: 0 f64
 // @concrete:
 // | File
 // |   ExpressionStatement
 // |     LiteralExpression
 // |       Number:'"42"'
 // |     Semicolon:'";"'
-
-42;
-
-// @type: 129 f64
diff --git a/fine/tests/expression/strings.fine b/fine/tests/expression/strings.fine
index b179635f..32fe9eab 100644
--- a/fine/tests/expression/strings.fine
+++ b/fine/tests/expression/strings.fine
@@ -1,3 +1,7 @@
+"Hello " + 'world!';
+
+// @no-errors
+// @type: 9 string
 // @concrete:
 // | File
 // |   ExpressionStatement
@@ -8,7 +12,3 @@
 // |       LiteralExpression
 // |         String:'"'world!'"'
 // |     Semicolon:'";"'
-//
-"Hello " + 'world!';
-
-// @type: 261 string
\ No newline at end of file