diff --git a/json-schema-converter/src/main/java/io/confluent/connect/json/JsonSchemaData.java b/json-schema-converter/src/main/java/io/confluent/connect/json/JsonSchemaData.java
index 0b5743f88f7..85af5c5d930 100644
--- a/json-schema-converter/src/main/java/io/confluent/connect/json/JsonSchemaData.java
+++ b/json-schema-converter/src/main/java/io/confluent/connect/json/JsonSchemaData.java
@@ -1178,6 +1178,7 @@ private Schema allOfToConnectSchema(
         // This is a number or integer with a format
         return toConnectSchema(ctx, numberSchema, version, forceOptional);
       }
+      return toConnectSchema(ctx, stringSchema, version, forceOptional);
     }
     throw new IllegalArgumentException("Unsupported criterion "
         + combinedSchema.getCriterion() + " for " + combinedSchema);