diff --git a/esphome/platformio/library.py b/esphome/platformio/library.py
index 049d4f3b87..999b1d3f11 100644
--- a/esphome/platformio/library.py
+++ b/esphome/platformio/library.py
@@ -994,7 +994,10 @@ def convert_libraries(
                 dep_name = dependency.get("name")
                 if (
                     isinstance(dep_name, str)
-                    and _node_key(dep_name, None, None)[0] in nodes
+                    # _node_key raises for a malformed URL-ish name; that
+                    # entry belongs to the warning below, not a traceback
+                    and "://" not in dep_name
+                    and _node_key(dep_name, None, None)[0] in top_level_keys
                 ):
                     # Already requested top-level: present in the build, not
                     # a drop (a false warning teaches users to ignore the
diff --git a/tests/unit_tests/test_platformio_library.py b/tests/unit_tests/test_platformio_library.py
index 8202658675..4b5b4508a0 100644
--- a/tests/unit_tests/test_platformio_library.py
+++ b/tests/unit_tests/test_platformio_library.py
@@ -665,3 +665,17 @@ def test_versionless_dependency_requested_top_level_stays_quiet(
         _backend(),
     )
     assert "has no version to resolve" not in caplog.text
+
+
+def test_versionless_url_ish_dependency_name_warns_cleanly(
+    tmp_path, monkeypatch, caplog: pytest.LogCaptureFixture
+) -> None:
+    """A malformed URL-ish dependency name falls to the drop warning, never
+    a RuntimeError out of the key parser."""
+    _patch_download_with_manifests(
+        monkeypatch,
+        tmp_path,
+        {"esphome/A": {"name": "A", "dependencies": [{"name": "file://"}]}},
+    )
+    convert_libraries([Library("esphome/A", None, None)], _backend())
+    assert "'file://' of esphome/A has no version to resolve" in caplog.text