diff --git a/Sources/SwiftKuery/Utils.swift b/Sources/SwiftKuery/Utils.swift
index 9aabd06b..839a3213 100644
--- a/Sources/SwiftKuery/Utils.swift
+++ b/Sources/SwiftKuery/Utils.swift
@@ -44,7 +44,8 @@ struct Utils {
             }
             return "'\(String(describing: value))'"
         default:
-            return String(describing: item)
+            let val = String(describing: item)
+            return val == "nil" ? "NULL" : val
         }
     }
         
diff --git a/Tests/SwiftKueryTests/TestInsert.swift b/Tests/SwiftKueryTests/TestInsert.swift
index 4d74bd4c..1d38845e 100644
--- a/Tests/SwiftKueryTests/TestInsert.swift
+++ b/Tests/SwiftKueryTests/TestInsert.swift
@@ -66,6 +66,13 @@ class TestInsert: XCTestCase {
         query = "INSERT INTO \"tableInsert\" (\"a\", \"b\") VALUES ('banana', 17) RETURNING *"
         XCTAssertEqual(kuery, query, "\nError in query construction: \n\(kuery) \ninstead of \n\(query)")
         
+        let optionalString: String? = nil
+        i = Insert(into: t, columns: [t.a, t.b], values: ["banana", optionalString as Any])
+            .suffix("RETURNING *")
+        kuery = connection.descriptionOf(query: i)
+        query = "INSERT INTO \"tableInsert\" (\"a\", \"b\") VALUES ('banana', NULL) RETURNING *"
+        XCTAssertEqual(kuery, query, "\nError in query construction: \n\(kuery) \ninstead of \n\(query)")
+        
         i = Insert(into: t, rows: [["apple", 17], ["banana", -7], ["banana", 27]])
         kuery = connection.descriptionOf(query: i)
         query = "INSERT INTO \"tableInsert\" VALUES ('apple', 17), ('banana', -7), ('banana', 27)"