diff --git a/kasa/deviceconfig.py b/kasa/deviceconfig.py
index f317ccb1..4ea255a4 100644
--- a/kasa/deviceconfig.py
+++ b/kasa/deviceconfig.py
@@ -165,7 +165,7 @@ class DeviceConfig:
         exclude_credentials: bool = False,
     ) -> Dict[str, Dict[str, str]]:
         """Convert device config to dict."""
-        if credentials_hash or exclude_credentials:
+        if credentials_hash is not None or exclude_credentials:
             self.credentials = None
         if credentials_hash:
             self.credentials_hash = credentials_hash
diff --git a/kasa/tests/test_deviceconfig.py b/kasa/tests/test_deviceconfig.py
index 22d42b81..43282915 100644
--- a/kasa/tests/test_deviceconfig.py
+++ b/kasa/tests/test_deviceconfig.py
@@ -35,7 +35,21 @@ def test_credentials_hash():
     assert config2.credentials is None
 
 
-def test_no_credentials_serialization():
+def test_blank_credentials_hash():
+    config = DeviceConfig(
+        host="Foo",
+        http_client=httpx.AsyncClient(),
+        credentials=Credentials("foo", "bar"),
+    )
+    config_dict = config.to_dict(credentials_hash="")
+    config_json = json_dumps(config_dict)
+    config2_dict = json_loads(config_json)
+    config2 = DeviceConfig.from_dict(config2_dict)
+    assert config2.credentials_hash is None
+    assert config2.credentials is None
+
+
+def test_exclude_credentials():
     config = DeviceConfig(
         host="Foo",
         http_client=httpx.AsyncClient(),