diff --git a/vulnerabilities/improver.py b/vulnerabilities/improver.py
index 9b46cce0a..a7554001f 100644
--- a/vulnerabilities/improver.py
+++ b/vulnerabilities/improver.py
@@ -78,7 +78,7 @@ def to_dict(self):
         """
         return {
             "vulnerability_id": self.vulnerability_id,
-            "aliases": [alias for alias in self.aliases],
+            "aliases": self.aliases,
             "confidence": self.confidence,
             "summary": self.summary,
             "affected_purls": [affected_purl.to_dict() for affected_purl in self.affected_purls],
@@ -91,7 +91,7 @@ def to_dict(self):
     def from_advisory_data(cls, advisory_data, confidence, fixed_purl, affected_purls=None):
         """
         Return an Inference object while keeping the same values as of advisory_data
-        for vulnerability_id, summary and references
+        for aliases, summary and references
         """
         return cls(
             aliases=advisory_data.aliases,
diff --git a/vulnerabilities/tests/test_improver.py b/vulnerabilities/tests/test_improver.py
new file mode 100644
index 000000000..ed524a991
--- /dev/null
+++ b/vulnerabilities/tests/test_improver.py
@@ -0,0 +1,70 @@
+#
+# Copyright (c) nexB Inc. and others. All rights reserved.
+# VulnerableCode is a trademark of nexB Inc.
+# SPDX-License-Identifier: Apache-2.0
+# See http://www.apache.org/licenses/LICENSE-2.0 for the license text.
+# See https://github.com/nexB/vulnerablecode for support or download.
+# See https://aboutcode.org for more information about nexB OSS projects.
+#
+
+import pytest
+
+from vulnerabilities.importer import AdvisoryData
+from vulnerabilities.importer import Reference
+from vulnerabilities.improver import MAX_CONFIDENCE
+from vulnerabilities.improver import Inference
+from vulnerabilities.improver import PackageURL
+
+
+def test_empty_inference_raises_exception():
+    with pytest.raises(AssertionError):
+        Inference()
+
+
+def test_inference_to_dict_method_with_vulnerability_id():
+    inference = Inference(vulnerability_id="vulcoid-1337")
+    expected = {
+        "vulnerability_id": "vulcoid-1337",
+        "aliases": [],
+        "confidence": MAX_CONFIDENCE,
+        "summary": "",
+        "affected_purls": [],
+        "fixed_purl": None,
+        "references": [],
+    }
+    assert expected == inference.to_dict()
+
+
+def test_inference_to_dict_method_with_purls():
+    purl = PackageURL(type="dummy", namespace="rick", name="jalebi", version="1")
+    inference = Inference(affected_purls=[purl], fixed_purl=purl)
+    expected = {
+        "vulnerability_id": None,
+        "aliases": [],
+        "confidence": MAX_CONFIDENCE,
+        "summary": "",
+        "affected_purls": [purl.to_dict()],
+        "fixed_purl": purl.to_dict(),
+        "references": [],
+    }
+    assert expected == inference.to_dict()
+
+
+def test_inference_to_dict_method_with_versionless_purls_raises_exception():
+    versionless_purl = PackageURL(type="dummy", namespace="rick", name="gulabjamun")
+    with pytest.raises(AssertionError):
+        Inference(affected_purls=[versionless_purl], fixed_purl=versionless_purl)
+
+
+def test_inference_from_advisory_data():
+    aliases = ["lalmohan", "gulabjamun"]
+    summary = "really tasty sweets"
+    references = [Reference(url="http://localhost")]
+    advisory_data = AdvisoryData(aliases=aliases, summary=summary, references=references)
+    fixed_purl = PackageURL(name="mithai", version="1", type="sweets")
+    inference = Inference.from_advisory_data(
+        advisory_data=advisory_data, fixed_purl=fixed_purl, confidence=MAX_CONFIDENCE
+    )
+    assert inference == Inference(
+        aliases=aliases, summary=summary, references=references, fixed_purl=fixed_purl
+    )