diff --git a/qgis-app/plugins/forms.py b/qgis-app/plugins/forms.py
index a179e1fe..0884bd19 100644
--- a/qgis-app/plugins/forms.py
+++ b/qgis-app/plugins/forms.py
@@ -195,7 +195,7 @@ def clean_package(self):
         """
         package = self.cleaned_data.get("package")
         try:
-            self.cleaned_data.update(validator(package))
+            self.cleaned_data.update(validator(package, is_new=True))
         except ValidationError as e:
             msg = _(
                 "There were errors reading plugin package (please check also your plugin's metadata)."
diff --git a/qgis-app/plugins/tests/test_validator.py b/qgis-app/plugins/tests/test_validator.py
index c96ba947..67fc919f 100644
--- a/qgis-app/plugins/tests/test_validator.py
+++ b/qgis-app/plugins/tests/test_validator.py
@@ -211,6 +211,33 @@ def test_zipfile_with_gitignore(self, mock_namelist):
         )
 
 
+class TestValidatorInvalidPackageName(TestCase):
+    """Test if plugin's directory is not PEP8 compliant """
+
+    def setUp(self) -> None:
+        invalid_package_name = os.path.join(TESTFILE_DIR, "invalid_package_name.zip_")
+        self.plugin_package = open(invalid_package_name, "rb")
+
+    def tearDown(self):
+        self.plugin_package.close()
+
+    # Package name does not match PEP8
+    def test_new_plugin_invalid_package_name(self):
+        self.assertRaises(
+            ValidationError,
+            validator,
+            InMemoryUploadedFile(
+                self.plugin_package,
+                field_name="tempfile",
+                name="testfile.zip",
+                content_type="application/zip",
+                size=39889,
+                charset="utf8",
+            ),
+            is_new=True
+        )
+
+
 class TestLicenseValidator(TestCase):
     """Test if zipfile contains LICENSE file """    
 
diff --git a/qgis-app/plugins/tests/testfiles/invalid_package_name.zip_ b/qgis-app/plugins/tests/testfiles/invalid_package_name.zip_
new file mode 100644
index 00000000..24026d2d
Binary files /dev/null and b/qgis-app/plugins/tests/testfiles/invalid_package_name.zip_ differ
diff --git a/qgis-app/plugins/validator.py b/qgis-app/plugins/validator.py
index a6a9f2b2..639c03a8 100644
--- a/qgis-app/plugins/validator.py
+++ b/qgis-app/plugins/validator.py
@@ -149,7 +149,7 @@ def error_check_if_exist(url: str)->bool:
     )
 
 
-def validator(package):
+def validator(package, is_new: bool = False):
     """
     Analyzes a zipped file, returns metadata if success, False otherwise.
     If the new icon metadata is found, an inmemory file object is also returned
@@ -162,6 +162,7 @@ def validator(package):
         * mandatory metadata: ('name', 'description', 'version', 'qgisMinimumVersion', 'author', 'email')
         * package_name regexp: [A-Za-z][A-Za-z0-9-_]+
         * author regexp: [^/]+
+        * New plugins package_name is PEP8 compliant
 
     """
     try:
@@ -243,6 +244,15 @@ def validator(package):
                 "Cannot find a folder inside the compressed package: this does not seems a valid plugin"
             )
         )
+    # Check if package_name is PEP 8 compliant
+    if is_new and not package_name.isidentifier():
+        raise ValidationError(
+            _(
+                "The name of the top level directory inside the zip package must be PEP 8 compliant: "
+                "a valid Python identifier, which means it must start with a letter or underscore, "
+                "and can only contain letters, digits, and underscores."
+            )
+        )
 
     # Cuts the trailing slash
     if package_name.endswith("/"):