diff --git a/pdm/models/project_info.py b/pdm/models/project_info.py
index 5b205a60e6..975608fa63 100644
--- a/pdm/models/project_info.py
+++ b/pdm/models/project_info.py
@@ -2,21 +2,15 @@
 
 import itertools
 import sys
-from typing import Any, Iterator, List
+from typing import Any, Iterator
 
 from pdm import termui
 from pdm.pep517.metadata import Metadata
 
 if sys.version_info >= (3, 8):
-    from email.message import Message as DistributionMetadata
     from importlib.metadata import Distribution
 else:
     from importlib_metadata import Distribution
-    from importlib_metadata._meta import PackageMetadata as DistributionMetadata
-
-
-def get_as_dot_list(metadata: DistributionMetadata, key: str) -> List[str]:
-    return metadata.get(key, "").split(",")
 
 
 class ProjectInfo:
@@ -30,8 +24,8 @@ def __init__(self, metadata: Distribution | Metadata) -> None:
 
     def _parse(self, data: Distribution) -> dict[str, Any]:
         metadata = data.metadata
-        keywords = get_as_dot_list(metadata, "Keywords")
-        platforms = get_as_dot_list(metadata, "Platform")
+        keywords = metadata.get("Keywords", "").replace(",", ", ")
+        platform = metadata.get("Platform", "").replace(",", ", ")
         project_urls = {
             k.strip(): v.strip()
             for k, v in (row.split(",") for row in metadata.get_all("Project-URL", []))
@@ -44,8 +38,8 @@ def _parse(self, data: Distribution) -> dict[str, Any]:
             "email": metadata.get("Author-email", ""),
             "license": metadata.get("License", ""),
             "requires-python": metadata.get("Requires-Python", ""),
-            "platform": ", ".join(platforms),
-            "keywords": ", ".join(keywords),
+            "platform": platform,
+            "keywords": keywords,
             "homepage": metadata.get("Home-page", ""),
             "project-urls": [": ".join(parts) for parts in project_urls.items()],
         }