diff --git a/platformio/package/manifest/model.py b/platformio/package/manifest/model.py
index 27684eb1..f881a370 100644
--- a/platformio/package/manifest/model.py
+++ b/platformio/package/manifest/model.py
@@ -56,7 +56,7 @@ class ManifestModel(DataModel):
     )
     description = DataField(max_length=1000, required=True)
     keywords = DataField(
-        type=ListOfType(DataField(max_length=255, regex=r"^[a-z\d\- ]+$")),
+        type=ListOfType(DataField(max_length=255, regex=r"^[a-z\d\-\+\. ]+$")),
         required=True,
     )
     authors = DataField(type=ListOfType(AuthorModel), required=True)
diff --git a/platformio/package/manifest/parser.py b/platformio/package/manifest/parser.py
index 799e1a58..4e6399f3 100644
--- a/platformio/package/manifest/parser.py
+++ b/platformio/package/manifest/parser.py
@@ -149,7 +149,7 @@ class BaseManifestParser(object):
             or not isinstance(examples, list)
             or not all(isinstance(v, dict) for v in examples)
         ):
-            data["examples"] = None
+            examples = None
         if not examples and self.package_dir:
             data["examples"] = self.parse_examples_from_dir(self.package_dir)
         if "examples" in data and not data["examples"]:
diff --git a/tests/test_pkgmanifest.py b/tests/test_pkgmanifest.py
index 0b2fa58d..e8b827d6 100644
--- a/tests/test_pkgmanifest.py
+++ b/tests/test_pkgmanifest.py
@@ -427,7 +427,9 @@ def test_package_json_model():
 
 def test_examples_from_dir(tmpdir_factory):
     package_dir = tmpdir_factory.mktemp("project")
-    package_dir.join("library.json").write('{"name": "pkg", "version": "1.0.0"}')
+    package_dir.join("library.json").write(
+        '{"name": "pkg", "version": "1.0.0", "examples": ["examples/*/*.pde"]}'
+    )
     examples_dir = package_dir.mkdir("examples")
 
     # PlatformIO project #1