diff --git a/swh/indexer/metadata_dictionary/cff.py b/swh/indexer/metadata_dictionary/cff.py
--- a/swh/indexer/metadata_dictionary/cff.py
+++ b/swh/indexer/metadata_dictionary/cff.py
@@ -42,16 +42,16 @@
             author_data: Dict[str, Optional[Union[str, Dict]]] = {
                 "@type": SCHEMA_URI + "Person"
             }
-            if "orcid" in author:
+            if "orcid" in author and isinstance(author["orcid"], str):
                 author_data["@id"] = author["orcid"]
-            if "affiliation" in author:
+            if "affiliation" in author and isinstance(author["affiliation"], str):
                 author_data[SCHEMA_URI + "affiliation"] = {
                     "@type": SCHEMA_URI + "Organization",
                     SCHEMA_URI + "name": author["affiliation"],
                 }
-            if "family-names" in author:
+            if "family-names" in author and isinstance(author["family-names"], str):
                 author_data[SCHEMA_URI + "familyName"] = author["family-names"]
-            if "given-names" in author:
+            if "given-names" in author and isinstance(author["given-names"], str):
                 author_data[SCHEMA_URI + "givenName"] = author["given-names"]
 
             result.append(author_data)
diff --git a/swh/indexer/tests/test_metadata.py b/swh/indexer/tests/test_metadata.py
--- a/swh/indexer/tests/test_metadata.py
+++ b/swh/indexer/tests/test_metadata.py
@@ -212,6 +212,55 @@
         # then
         assert expected == result
 
+    def test_cff_empty_fields(self):
+        """
+        testing CITATION.cff translation
+        """
+        # given
+        content = """# YAML 1.2
+  authors:
+  -
+    affiliation: "Netherlands eScience Center"
+    family-names:
+    given-names: Tom
+  -
+    affiliation: "Humboldt-Universität zu Berlin"
+    family-names: Druskat
+    orcid:
+    given-names: Stephan
+        """.encode(
+            "utf-8"
+        )
+
+        expected = {
+            "@context": "https://doi.org/10.5063/schema/codemeta-2.0",
+            "type": "SoftwareSourceCode",
+            "author": [
+                {
+                    "type": "Person",
+                    "affiliation": {
+                        "type": "Organization",
+                        "name": "Netherlands eScience Center",
+                    },
+                    "givenName": "Tom",
+                },
+                {
+                    "type": "Person",
+                    "affiliation": {
+                        "type": "Organization",
+                        "name": "Humboldt-Universität zu Berlin",
+                    },
+                    "familyName": "Druskat",
+                    "givenName": "Stephan",
+                },
+            ],
+        }
+
+        # when
+        result = self.cff_mapping.translate(content)
+        # then
+        assert expected == result
+
     def test_compute_metadata_npm(self):
         """
         testing only computation of metadata with hard_mapping_npm