diff --git a/src/LoggerHelper.ts b/src/LoggerHelper.ts
index 2ef10e5f..52665e19 100644
--- a/src/LoggerHelper.ts
+++ b/src/LoggerHelper.ts
@@ -334,6 +334,8 @@ export class LoggerHelper {
       return value;
     };
 
-    return LoggerHelper.cloneObjectRecursively(obj, maskValuesFn);
+    return obj != null
+      ? LoggerHelper.cloneObjectRecursively(obj, maskValuesFn)
+      : obj;
   }
 }
diff --git a/tests/parameter.test.ts b/tests/parameter.test.ts
new file mode 100644
index 00000000..a7bd68f4
--- /dev/null
+++ b/tests/parameter.test.ts
@@ -0,0 +1,57 @@
+import "ts-jest";
+import { IStd, Logger } from "../src";
+import { doesLogContain } from "./helper";
+import exp = require("constants");
+
+const stdOut: string[] = [];
+const stdErr: string[] = [];
+
+const logger: Logger = new Logger({
+  stdOut: {
+    write: (print: string) => {
+      stdOut.push(print);
+    },
+  },
+  stdErr: {
+    write: (print: string) => {
+      stdErr.push(print);
+    },
+  },
+});
+
+describe("Logger: Parameter", () => {
+  beforeEach(() => {
+    stdOut.length = 0;
+    stdErr.length = 0;
+  });
+
+  test("undefined", (): void => {
+    logger.silly(undefined);
+    expect(doesLogContain(stdOut, "SILLY")).toBeTruthy();
+    expect(doesLogContain(stdOut, "undefined")).toBeTruthy();
+  });
+
+  test("null", (): void => {
+    logger.silly(null);
+    expect(doesLogContain(stdOut, "SILLY")).toBeTruthy();
+    expect(doesLogContain(stdOut, "null")).toBeTruthy();
+  });
+
+  test("boolean", (): void => {
+    logger.silly(true);
+    expect(doesLogContain(stdOut, "SILLY")).toBeTruthy();
+    expect(doesLogContain(stdOut, "true")).toBeTruthy();
+  });
+
+  test("number", (): void => {
+    logger.silly(0);
+    expect(doesLogContain(stdOut, "SILLY")).toBeTruthy();
+    expect(doesLogContain(stdOut, "0")).toBeTruthy();
+  });
+
+  test("string", (): void => {
+    logger.silly("string");
+    expect(doesLogContain(stdOut, "SILLY")).toBeTruthy();
+    expect(doesLogContain(stdOut, "string")).toBeTruthy();
+  });
+});