diff --git a/package.json b/package.json
index 3848008..5cf5477 100644
--- a/package.json
+++ b/package.json
@@ -1,6 +1,6 @@
 {
   "name": "cache-control-parser",
-  "version": "2.0.5",
+  "version": "2.0.6",
   "description": "A humble cache-control parser",
   "homepage": "https://github.com/etienne-martin/cache-control-parser",
   "keywords": [
diff --git a/src/cache-control-parser.test.ts b/src/cache-control-parser.test.ts
index 8bf40df..004dac0 100644
--- a/src/cache-control-parser.test.ts
+++ b/src/cache-control-parser.test.ts
@@ -6,11 +6,11 @@ import {
 
 const testSuite = (parser: typeof parse, stringifier: typeof stringify) => {
   describe("parse", () => {
-    test("should parse empty cache-control header", () => {
+    it("should parse empty cache-control header", () => {
       expect(parser("")).toEqual({});
     });
 
-    test("should parse both boolean and numeric directives", () => {
+    it("should parse both boolean and numeric directives", () => {
       expect(
         parser(
           "max-age=1, s-maxage=2, stale-while-revalidate=3, stale-if-error=4, public, private, no-store, no-cache, must-revalidate, proxy-revalidate, immutable, no-transform"
@@ -31,7 +31,7 @@ const testSuite = (parser: typeof parse, stringifier: typeof stringify) => {
       });
     });
 
-    test("should trim directives", () => {
+    it("should trim directives", () => {
       expect(
         parser("   max-age =  60 ,    s-maxage  = 3600 , public   ")
       ).toEqual({
@@ -41,7 +41,7 @@ const testSuite = (parser: typeof parse, stringifier: typeof stringify) => {
       });
     });
 
-    test("should be case-insensitive", () => {
+    it("should be case-insensitive", () => {
       expect(parser("Max-Age=1, S-MAXAGE=2, Stale-While-Revalidate=3")).toEqual(
         {
           "max-age": 1,
@@ -51,20 +51,20 @@ const testSuite = (parser: typeof parse, stringifier: typeof stringify) => {
       );
     });
 
-    test("should support directives that are not separated by spaces", () => {
+    it("should support directives that are not separated by spaces", () => {
       expect(parser("max-age=60,public")).toEqual({
         "max-age": 60,
         public: true
       });
     });
 
-    test("should override previously declared directives", () => {
+    it("should override previously declared directives", () => {
       expect(parser("max-age=1, max-age=2")).toEqual({
         "max-age": 2
       });
     });
 
-    test("should ignore invalid directives", () => {
+    it("should ignore invalid directives", () => {
       expect(
         parser(
           "max-age=NaN, s-maxage=NaN, stale-while-revalidate=NaN, stale-if-error=NaN"
@@ -72,27 +72,27 @@ const testSuite = (parser: typeof parse, stringifier: typeof stringify) => {
       ).toEqual({});
     });
 
-    test("should not override previously declared directives if the directive is invalid", () => {
+    it("should not override previously declared directives if the directive is invalid", () => {
       expect(parser("max-age=1, max-age=NaN")).toEqual({
         "max-age": 1
       });
     });
 
-    test("should ignore unknown directives", () => {
+    it("should ignore unknown directives", () => {
       expect(parser("unknown-directive")).toEqual({});
     });
 
-    test("should ignore unknown directives", () => {
+    it("should ignore unknown directives", () => {
       expect(parser("unknown-directive=value")).toEqual({});
     });
   });
 
   describe("stringify", () => {
-    test("should stringify empty cache control", () => {
+    it("should stringify empty cache control", () => {
       expect(stringifier({})).toEqual("");
     });
 
-    test("should stringify both boolean and numeric directives", () => {
+    it("should stringify both boolean and numeric directives", () => {
       expect(
         stringifier({
           "max-age": 1,
@@ -113,7 +113,7 @@ const testSuite = (parser: typeof parse, stringifier: typeof stringify) => {
       );
     });
 
-    test("should leave out unsupported directives", () => {
+    it("should leave out unsupported directives", () => {
       expect(
         stringifier({
           "max-age": 1,
@@ -122,6 +122,17 @@ const testSuite = (parser: typeof parse, stringifier: typeof stringify) => {
         } as CacheControl)
       ).toEqual("max-age=1");
     });
+
+    it("should not include falsy booleans", () => {
+      expect(
+        stringifier({
+          "max-age": 1,
+          public: false,
+          private: false,
+          immutable: false
+        } as CacheControl)
+      ).toEqual("max-age=1");
+    });
   });
 };
 
diff --git a/src/cache-control-parser.ts b/src/cache-control-parser.ts
index 14c5602..20e2d3a 100644
--- a/src/cache-control-parser.ts
+++ b/src/cache-control-parser.ts
@@ -97,7 +97,7 @@ export const stringify = (cacheControl: CacheControl) => {
 
     switch (typeof value) {
       case "boolean":
-        directives.push(`${key}`);
+        value && directives.push(`${key}`);
         break;
       case "number":
         directives.push(`${key}=${value}`);