diff --git a/Sources/JSONAPITestLib/Optional+Literal.swift b/Sources/JSONAPITestLib/Optional+Literal.swift
new file mode 100644
index 0000000..7c9087f
--- /dev/null
+++ b/Sources/JSONAPITestLib/Optional+Literal.swift
@@ -0,0 +1,30 @@
+//
+//  Optional+Literal.swift
+//  JSONAPITestLib
+//
+//  Created by Mathew Polzin on 11/29/18.
+//
+
+extension Optional: ExpressibleByUnicodeScalarLiteral where Wrapped: ExpressibleByUnicodeScalarLiteral {
+	public typealias UnicodeScalarLiteralType =  Wrapped.UnicodeScalarLiteralType
+
+	public init(unicodeScalarLiteral value: UnicodeScalarLiteralType) {
+		self = .some(Wrapped(unicodeScalarLiteral: value))
+	}
+}
+
+extension Optional: ExpressibleByExtendedGraphemeClusterLiteral where Wrapped: ExpressibleByExtendedGraphemeClusterLiteral {
+	public typealias ExtendedGraphemeClusterLiteralType =  Wrapped.ExtendedGraphemeClusterLiteralType
+
+	public init(extendedGraphemeClusterLiteral value: ExtendedGraphemeClusterLiteralType) {
+		self = .some(Wrapped(extendedGraphemeClusterLiteral: value))
+	}
+}
+
+extension Optional: ExpressibleByStringLiteral where Wrapped: ExpressibleByStringLiteral {
+	public typealias StringLiteralType = Wrapped.StringLiteralType
+
+	public init(stringLiteral value: StringLiteralType) {
+		self = .some(Wrapped(stringLiteral: value))
+	}
+}
diff --git a/Sources/JSONAPITestLib/Relationship+Literal.swift b/Sources/JSONAPITestLib/Relationship+Literal.swift
index 42fdc6d..0dc586e 100644
--- a/Sources/JSONAPITestLib/Relationship+Literal.swift
+++ b/Sources/JSONAPITestLib/Relationship+Literal.swift
@@ -9,10 +9,35 @@ import JSONAPI
 
 extension ToOneRelationship: ExpressibleByNilLiteral where Relatable.WrappedIdentifier: ExpressibleByNilLiteral {
 	public init(nilLiteral: ()) {
+
 		self.init(id: Relatable.WrappedIdentifier(nilLiteral: ()))
 	}
 }
 
+extension ToOneRelationship: ExpressibleByUnicodeScalarLiteral where Relatable.WrappedIdentifier: ExpressibleByUnicodeScalarLiteral {
+	public typealias UnicodeScalarLiteralType =  Relatable.WrappedIdentifier.UnicodeScalarLiteralType
+
+	public init(unicodeScalarLiteral value: UnicodeScalarLiteralType) {
+		self.init(id: Relatable.WrappedIdentifier(unicodeScalarLiteral: value))
+	}
+}
+
+extension ToOneRelationship: ExpressibleByExtendedGraphemeClusterLiteral where Relatable.WrappedIdentifier: ExpressibleByExtendedGraphemeClusterLiteral {
+	public typealias ExtendedGraphemeClusterLiteralType =  Relatable.WrappedIdentifier.ExtendedGraphemeClusterLiteralType
+
+	public init(extendedGraphemeClusterLiteral value: ExtendedGraphemeClusterLiteralType) {
+		self.init(id: Relatable.WrappedIdentifier(extendedGraphemeClusterLiteral: value))
+	}
+}
+
+extension ToOneRelationship: ExpressibleByStringLiteral where Relatable.WrappedIdentifier: ExpressibleByStringLiteral {
+	public typealias StringLiteralType = Relatable.WrappedIdentifier.StringLiteralType
+
+	public init(stringLiteral value: StringLiteralType) {
+		self.init(id: Relatable.WrappedIdentifier(stringLiteral: value))
+	}
+}
+
 extension ToManyRelationship: ExpressibleByArrayLiteral {
 	public typealias ArrayLiteralElement = Relatable.Identifier
 
diff --git a/Tests/JSONAPITests/JSONAPITestLib/Relationship+LiteralTests.swift b/Tests/JSONAPITests/JSONAPITestLib/Relationship+LiteralTests.swift
index 896535e..42ec030 100644
--- a/Tests/JSONAPITests/JSONAPITestLib/Relationship+LiteralTests.swift
+++ b/Tests/JSONAPITests/JSONAPITestLib/Relationship+LiteralTests.swift
@@ -18,6 +18,11 @@ class Relationship_LiteralTests: XCTestCase {
 	func test_ArrayLiteral() {
 		XCTAssertEqual(ToManyRelationship<TestEntity>(ids: ["1", "2", "3"]), ["1", "2", "3"])
 	}
+
+	func test_StringLiteral() {
+		XCTAssertEqual(ToOneRelationship<TestEntity>(id: "123"), "123")
+		XCTAssertEqual(ToOneRelationship<TestEntity?>(id: "123"), "123")
+	}
 }
 
 // MARK: - Test types