diff --git a/norminette/__main__.py b/norminette/__main__.py
index 264dcca..8ee3120 100644
--- a/norminette/__main__.py
+++ b/norminette/__main__.py
@@ -136,7 +136,7 @@ def main():
         except KeyboardInterrupt:
             sys.exit(1)
     errors = format(files)
-    print(errors)
+    print(errors, end='')
     sys.exit(1 if len(file.errors) else 0)
 
 
diff --git a/norminette/errors.py b/norminette/errors.py
index 6af05b9..e8818f7 100644
--- a/norminette/errors.py
+++ b/norminette/errors.py
@@ -179,6 +179,7 @@ def __str__(self) -> str:
                 highlight = error.highlights[0]
                 output += f"\n{error.level}: {error.name:<20} "
                 output += f"(line: {highlight.lineno:>3}, col: {highlight.column:>3}):\t{error.text}"
+            output += '\n'
         return output
 
 
@@ -194,7 +195,7 @@ def __str__(self):
         output = {
             "files": files,
         }
-        return json.dumps(output, separators=(',', ':'))
+        return json.dumps(output, separators=(',', ':')) + '\n'
 
 
 formatters = (
diff --git a/tests/rules/rules_generator_test.py b/tests/rules/rules_generator_test.py
index 979b9e6..19f86ca 100644
--- a/tests/rules/rules_generator_test.py
+++ b/tests/rules/rules_generator_test.py
@@ -25,7 +25,7 @@ def test_rule_for_file(file, capsys):
     context = Context(file, list(lexer), debug=2)
     registry.run(context)
     errors = HumanizedErrorsFormatter(file)
-    print(errors)
+    print(errors, end='')
     captured = capsys.readouterr()
 
     assert captured.out == out_content
diff --git a/tests/test_errors.py b/tests/test_errors.py
index a65b999..be6636d 100644
--- a/tests/test_errors.py
+++ b/tests/test_errors.py
@@ -3,6 +3,7 @@
 from dataclasses import astuple
 
 import pytest
+from unittest.mock import patch
 
 from norminette.file import File
 from norminette.lexer import Lexer
@@ -10,6 +11,61 @@
 from norminette.registry import Registry
 from norminette.errors import JSONErrorsFormatter
 from norminette.errors import Error, Errors, Highlight as H
+from norminette.errors import HumanizedErrorsFormatter
+
+
+@pytest.mark.parametrize("files, expected_result, ", [it.values() for it in [
+        {
+            "files": [
+                File("/nium/a.c", "#include <stdio.h>"),
+                File("/nium/b.c", "int\tmain(void)\n{\n\treturn (1);\n}\n"),
+                File("/nium/c.c", "int\tfn(int n);\n"),
+            ],
+            "expected_result": "a.c: OK!\nb.c: OK!\nc.c: OK!\n",
+        },
+        {
+            "files": [
+                File("skyfall.c", "// Hello"),
+            ],
+            "expected_result": "skyfall.c: OK!\n",
+        },
+        {
+            "files": [
+                File("/nium/mortari.c", "#define TRUE 1"),
+                File("/nium/gensler.c", "int\tmain();\n"),
+            ],
+            "expected_result": (
+                "mortari.c: OK!\n"
+                "gensler.c: Error!\n"
+                "Error: NO_ARGS_VOID         (line:   1, col:  10):\tEmpty function argument requires void\n"
+            )
+        },
+        {
+            "files": [
+                File("/nium/john.c", "#define x"),
+                File("/nium/galt.c", "#define x"),
+            ],
+            "expected_result": (
+                "john.c: Error!\n"
+                "Error: MACRO_NAME_CAPITAL   (line:   1, col:   9):\tMacro name must be capitalized\n"
+                "galt.c: Error!\n"
+                "Error: MACRO_NAME_CAPITAL   (line:   1, col:   9):\tMacro name must be capitalized\n"
+            )
+        },
+    ]
+])
+def test_humanized_formatter_errored_file(files, expected_result):
+    registry = Registry()
+
+    with patch("norminette.rules.check_header.CheckHeader.run") as _:
+        for file in files:
+            lexer = Lexer(file)
+            context = Context(file, lexer.get_tokens())
+            registry.run(context)
+
+    formatter = HumanizedErrorsFormatter(files)
+    assert str(formatter) == expected_result
+
 
 tests = [
     {
@@ -47,7 +103,7 @@ def test_json_formatter_errored_file(file, test):
     Registry().run(context)
 
     formatter = JSONErrorsFormatter(file)
-    assert str(formatter) == json.dumps(test, separators=(',', ':'))
+    assert str(formatter) == json.dumps(test, separators=(',', ':')) + '\n'
 
 
 def test_error_from_name():