diff --git a/lib/formatting.js b/lib/formatting.js
index 48727da5..605b3099 100644
--- a/lib/formatting.js
+++ b/lib/formatting.js
@@ -153,8 +153,8 @@ const formatAs = {
             if (v.name === 'this') {
                 return formatValue(obj, v.fm);
             }
-            if ('default' in options) {
-                const d = options.default, value = typeof d === 'function' ? d.call(obj, v.name, obj) : d;
+            if ('def' in options) {
+                const d = options.def, value = typeof d === 'function' ? d.call(obj, v.name, obj) : d;
                 return formatValue(value, v.fm, obj);
             }
             if (options.partial) {
@@ -176,8 +176,8 @@ const formatAs = {
             if (idx < array.length) {
                 return formatValue(array[idx], v.fm);
             }
-            if ('default' in options) {
-                const d = options.default, value = typeof d === 'function' ? d.call(array, idx, array) : d;
+            if ('def' in options) {
+                const d = options.def, value = typeof d === 'function' ? d.call(array, idx, array) : d;
                 return formatValue(value, v.fm);
             }
             if (options.partial) {
@@ -806,7 +806,7 @@ const $as = {
      *
      * This option has no meaning when option `default` is present.
      *
-     * @param {*} [options.default]
+     * @param {*} [options.def]
      * Sets a default value for every variable that's missing, consequently preventing errors when encountering a variable
      * or property name that's missing within the formatting parameters.
      *
@@ -827,7 +827,7 @@ const $as = {
      * The function will throw an error, if any occurs during formatting.
      */
     format(query, values, options) {
-        options = npm.assertOptions(options, ['partial', 'default']);
+        options = npm.assertOptions(options, ['partial', 'def']);
         const ctf = getCTF(query);
         if (ctf) {
             query = ctf.toPostgres.call(query, query);
diff --git a/package.json b/package.json
index 44c8e469..c3c31b50 100644
--- a/package.json
+++ b/package.json
@@ -58,6 +58,6 @@
     "jasmine-node": "1.16.2",
     "jsdoc": "3.5.5",
     "pg-query-stream": "2.0.0",
-    "typescript": "3.3.3"
+    "typescript": "3.3.3333"
   }
 }
diff --git a/test/formatSpec.js b/test/formatSpec.js
index 2ee3098f..bc57d85d 100644
--- a/test/formatSpec.js
+++ b/test/formatSpec.js
@@ -778,9 +778,9 @@ describe('Method as.format', () => {
 
         describe('default', () => {
             it('must replace missing variables', () => {
-                expect(pgp.as.format('$1, $2', [1], {default: undefined})).toBe('1, null');
-                expect(pgp.as.format('$1, $2', [1], {default: null})).toBe('1, null');
-                expect(pgp.as.format('${present}, ${missing}', {present: 1}, {default: 2})).toBe('1, 2');
+                expect(pgp.as.format('$1, $2', [1], {def: undefined})).toBe('1, null');
+                expect(pgp.as.format('$1, $2', [1], {def: null})).toBe('1, null');
+                expect(pgp.as.format('${present}, ${missing}', {present: 1}, {def: 2})).toBe('1, 2');
             });
             it('must invoke a callback correctly', () => {
                 let value, context, param;
@@ -793,13 +793,13 @@ describe('Method as.format', () => {
                 }
 
                 const arr = ['hi'];
-                expect(pgp.as.format('$1, $2', arr, {default: cb})).toBe('\'hi\', 123');
+                expect(pgp.as.format('$1, $2', arr, {def: cb})).toBe('\'hi\', 123');
                 expect(context === arr).toBe(true);
                 expect(param === arr).toBe(true);
                 expect(value).toBe(1);
 
                 const obj = {first: 'f'};
-                expect(pgp.as.format('${first}, ${  second^ \t}', obj, {default: cb})).toBe('\'f\', 123');
+                expect(pgp.as.format('${first}, ${  second^ \t}', obj, {def: cb})).toBe('\'f\', 123');
                 expect(context === obj).toBe(true);
                 expect(param === obj).toBe(true);
                 expect(value).toBe('second');
@@ -1030,7 +1030,7 @@ describe('Nested Named Parameters', () => {
 
     describe('default values', () => {
         it('must be formatted correctly', () => {
-            expect(pgp.as.format('${one.two.three}', {}, {'default': 123})).toBe('123');
+            expect(pgp.as.format('${one.two.three}', {}, {def: 123})).toBe('123');
         });
     });
 
@@ -1074,7 +1074,7 @@ describe('Nested Named Parameters', () => {
             });
         });
 
-        describe('for default values', () => {
+        describe('for "def" values', () => {
             it('must represent the source object', () => {
                 const obj = {
                     value: 1,
@@ -1085,15 +1085,15 @@ describe('Nested Named Parameters', () => {
                         }
                     }
                 };
-                expect(pgp.as.format('${one.two.three}', obj, {'default': (name, o) => o.value})).toBe('1');
+                expect(pgp.as.format('${one.two.three}', obj, {def: (name, o) => o.value})).toBe('1');
                 expect(pgp.as.format('${one.two.three}', obj, {
-                    'default': function () {
+                    def: function () {
                         return this.value;
                     }
                 })).toBe('1');
             });
             it('must pass in the full property name', () => {
-                expect(pgp.as.format('${one.two.three}', {}, {'default': name => name})).toBe('\'one.two.three\'');
+                expect(pgp.as.format('${one.two.three}', {}, {def: name => name})).toBe('\'one.two.three\'');
             });
         });
 
diff --git a/test/typescript/formatting.ts b/test/typescript/formatting.ts
index 7e3867af..b1db0e40 100644
--- a/test/typescript/formatting.ts
+++ b/test/typescript/formatting.ts
@@ -38,7 +38,7 @@ class CTF {
 
 const ctf = new CTF();
 
-const testCTF = pgp.as.format(ctf);
+const testCTF = pgp.as.format(ctf, null, {def: 1});
 
 const testFunc1 = pgp.as.func(() => {
 });
diff --git a/typescript/pg-promise.d.ts b/typescript/pg-promise.d.ts
index fd1fac19..15c2ee11 100644
--- a/typescript/pg-promise.d.ts
+++ b/typescript/pg-promise.d.ts
@@ -8,7 +8,7 @@
  */
 
 /////////////////////////////////////////
-// Requires pg-promise v8.5.3 or later.
+// Requires pg-promise v8.6.0 or later.
 /////////////////////////////////////////
 
 import * as XPromise from './ext-promise'; // External Promise Provider
@@ -36,7 +36,7 @@ declare namespace pgPromise {
 
     type TFormattingOptions = {
         partial?: boolean
-        default?: any
+        def?: any
     };
 
     interface ILostContext {