diff --git a/lib/make/colors.js b/lib/make/colors.js
index 959b575..929a992 100644
--- a/lib/make/colors.js
+++ b/lib/make/colors.js
@@ -8,9 +8,9 @@ const random = require('../random')
 class colors extends make {
   static any () {
     return random.pick([
-      this.rgb,
-      this.hsl,
-      this.keyword
+      colors.rgb,
+      colors.hsl,
+      colors.keyword
     ])
   }
 
diff --git a/lib/make/command.js b/lib/make/command.js
index 2648747..d6827be 100644
--- a/lib/make/command.js
+++ b/lib/make/command.js
@@ -58,11 +58,11 @@ class command extends make {
   }
 
   static name () {
-    return random.item(Object.keys(this.data()))
+    return random.item(Object.keys(command.data()))
   }
 
   static value (value) {
-    return random.pick(this.data()[name])
+    return random.pick(command.data()[name])
   }
 }
 
diff --git a/lib/make/files.js b/lib/make/files.js
index 76aac78..8b80d35 100644
--- a/lib/make/files.js
+++ b/lib/make/files.js
@@ -43,9 +43,9 @@ class files extends make {
 
   static any () {
     return random.pick([
-      this.image,
-      this.video,
-      this.audio
+      files.image,
+      files.video,
+      files.audio
     ])
   }
 }
diff --git a/lib/make/fonts.js b/lib/make/fonts.js
index 402812d..16ec092 100644
--- a/lib/make/fonts.js
+++ b/lib/make/fonts.js
@@ -56,9 +56,9 @@ class font extends make {
   }
 
   static family () {
-    let s = random.pick(this.familyName)
+    let s = random.pick(font.familyName)
     if (random.chance(8)) {
-      s += ', ' + random.pick(this.genericFamily)
+      s += ', ' + random.pick(font.genericFamily)
     }
     return s
   }
@@ -86,20 +86,20 @@ class font extends make {
   static font () {
     let s = ''
     if (random.chance(4)) {
-      s += random.pick(this.style) + ' '
+      s += random.pick(font.style) + ' '
     }
     if (random.chance(4)) {
-      s += random.pick(this.variant) + ' '
+      s += random.pick(font.variant) + ' '
     }
     if (random.chance(4)) {
-      s += random.pick(this.weight) + ' '
+      s += random.pick(font.weight) + ' '
     }
     if (random.chance(4)) {
       s += make.number.any() + '/'
     }
-    s += this.size()
+    s += font.size()
     s += ' '
-    s += this.family()
+    s += font.family()
     return s
   }
 }
diff --git a/lib/make/network.js b/lib/make/network.js
index c7ebe02..a1a16aa 100644
--- a/lib/make/network.js
+++ b/lib/make/network.js
@@ -56,7 +56,7 @@ class network extends make {
       ' ',
       random.pick([make.number.any]),
       ' ',
-      random.pick([this.goodHostnames]),
+      random.pick([network.goodHostnames]),
       ' ',
       random.pick([56187, make.number.any]),
       ' ',
@@ -69,7 +69,7 @@ class network extends make {
           ' ',
           random.pick(['raddr']),
           ' ',
-          random.pick([this.goodHostnames]),
+          random.pick([network.goodHostnames]),
           ' ',
           random.pick(['rport']),
           random.use([utils.block.block([' ', make.number.any])])
@@ -95,12 +95,12 @@ class network extends make {
     // https://tools.ietf.org/html/rfc7065#section-3.1
     return utils.block.block([
       // scheme
-      random.pick(this.PeerConnectionProtocols),
+      random.pick(network.PeerConnectionProtocols),
       ':',
       // turn-host
       random.pick([
-        this.any,
-        this.hostname
+        network.any,
+        network.hostname
       ]),
       // turn-port
       random.use([utils.block.block([':', make.number.any])]),
@@ -172,10 +172,10 @@ class network extends make {
 
   static hostname () {
     return random.pick([
-      this.randomIPv4,
-      this.randomIPv6,
-      this.goodHostnames,
-      this.badHostnames
+      network.randomIPv4,
+      network.randomIPv6,
+      network.goodHostnames,
+      network.badHostnames
     ])
   }
 
diff --git a/lib/make/text.js b/lib/make/text.js
index 9e0737a..e1ee21b 100644
--- a/lib/make/text.js
+++ b/lib/make/text.js
@@ -219,17 +219,17 @@ class text extends make {
   }
 
   static quotedString () {
-    return utils.common.quote(this.any())
+    return utils.common.quote(text.any())
   }
 
   static chars () {
     return random.pick([
-      this.controlChar,
-      this.token,
-      this.assignmentOperator,
-      this.arithmeticOperator,
-      String.fromCharCode(this.layoutCharCodes()),
-      String.fromCharCode(this.bidiCharCodes())
+      text.controlChar,
+      text.token,
+      text.assignmentOperator,
+      text.arithmeticOperator,
+      String.fromCharCode(text.layoutCharCodes()),
+      String.fromCharCode(text.bidiCharCodes())
     ])
   }
 
diff --git a/lib/make/typed.js b/lib/make/typed.js
index 3b8fdb1..5f957a6 100644
--- a/lib/make/typed.js
+++ b/lib/make/typed.js
@@ -78,27 +78,27 @@ class typed extends make {
 
   static any () {
     return random.choose([
-      [1, [this.byte, this.octet]],
-      [1, [this.short, this.unsignedShort]],
-      [1, [this.long, this.unsignedLong]],
-      [1, [this.float, this.unrestrictedFloat]],
-      [1, [this.double, this.unrestrictedDouble]],
+      [1, [typed.byte, typed.octet]],
+      [1, [typed.short, typed.unsignedShort]],
+      [1, [typed.long, typed.unsignedLong]],
+      [1, [typed.float, typed.unrestrictedFloat]],
+      [1, [typed.double, typed.unrestrictedDouble]],
       [1, [make.number.range, make.number.tiny]]
     ])
   }
 
   static arrayBuffer (byteLength = null) {
-    let length = (byteLength !== null) ? byteLength : this.unsignedShort()
+    let length = (byteLength !== null) ? byteLength : typed.unsignedShort()
     return 'new ArrayBuffer(' + length + ')'
   }
 
   static dataView (byteLength = null) {
-    let length = (byteLength !== null) ? byteLength : this.unsignedShort()
-    return 'new DataView(' + this.arrayBuffer(length) + ')'
+    let length = (byteLength !== null) ? byteLength : typed.unsignedShort()
+    return 'new DataView(' + typed.arrayBuffer(length) + ')'
   }
 
   static typedArray (byteLength = null) {
-    let length = (byteLength !== null) ? byteLength : this.unsignedShort()
+    let length = (byteLength !== null) ? byteLength : typed.unsignedShort()
     let arrType = random.item([
       'Int8', 'Uint8', 'Uint8Clamped',
       'Int16', 'Uint16',
@@ -119,11 +119,11 @@ class typed extends make {
   static bufferSource () {
     switch (random.number(4)) {
       case 0:
-        return this.arrayBuffer()
+        return typed.arrayBuffer()
       case 1:
-        return this.dataView()
+        return typed.dataView()
       default:
-        return this.typedArray()
+        return typed.typedArray()
     }
   }
 }
diff --git a/lib/make/uri.js b/lib/make/uri.js
index d65f2d9..cfa9fa3 100644
--- a/lib/make/uri.js
+++ b/lib/make/uri.js
@@ -44,9 +44,9 @@ class uri extends make {
 
   static any () {
     return random.choose([
-      [1, this.problematic],
-      [10, this.standard],
-      [10, this.namespace],
+      [1, uri.problematic],
+      [10, uri.standard],
+      [10, uri.namespace],
       [10, make.files.any]
     ])
   }
diff --git a/lib/make/webgl.js b/lib/make/webgl.js
index 828bbe7..bab4599 100644
--- a/lib/make/webgl.js
+++ b/lib/make/webgl.js
@@ -41,9 +41,9 @@ class webgl extends make {
   }
 
   static WebGLFormat () {
-    let internalformat = random.item(Object.keys(this.internalFormat))
-    let format = this.internalFormat[internalformat].format
-    let type = random.item(this.internalFormat[internalformat].type)
+    let internalformat = random.item(Object.keys(webgl.internalFormat))
+    let format = webgl.internalFormat[internalformat].format
+    let type = random.item(webgl.internalFormat[internalformat].type)
     return [internalformat, format, type]
   }
 
diff --git a/lib/random/random.js b/lib/random/random.js
index 541891f..63a1f61 100644
--- a/lib/random/random.js
+++ b/lib/random/random.js
@@ -12,10 +12,10 @@ class random {
    */
   static init (seed) {
     if (seed === null || seed === undefined) {
-      this.seed = new Date().getTime()
+      random.seed = new Date().getTime()
     }
-    this.twister = new MersenneTwister()
-    this.twister.seed(this.seed)
+    random.twister = new MersenneTwister()
+    random.twister.seed(random.seed)
   }
 
   /**
@@ -23,6 +23,9 @@ class random {
    * @param limit
    */
   static number (limit) {
+    if (!random.twister) {
+      throw new Error('random.init must be called first.')
+    }
     if (limit === null || limit === undefined) {
       limit = 0xffffffff
     }
@@ -30,7 +33,7 @@ class random {
     let y = (x * limit) >>> 0
     let r
     do {
-      r = this.twister.int32()
+      r = random.twister.int32()
     } while (y && r >= y) // eslint-disable-line no-unmodified-loop-condition
     return (r / x) >>> 0
   }
@@ -39,7 +42,10 @@ class random {
    * Returns a float in [0, 1). Uniform distribution.
    */
   static float () {
-    return this.twister.real2()
+    if (!random.twister) {
+      throw new Error('random.init must be called first.')
+    }
+    return random.twister.real2()
   }
 
   /**
@@ -48,11 +54,14 @@ class random {
    * @param limit
    */
   static range (start, limit) {
+    if (!random.twister) {
+      throw new Error('random.init must be called first.')
+    }
     if (isNaN(start) || isNaN(limit)) {
       logger.traceback()
       throw new TypeError(`random.range() received non-number type: (${start}, ${limit})`)
     }
-    return this.number(limit - start + 1) + start
+    return random.number(limit - start + 1) + start
   }
 
   /**
@@ -60,7 +69,7 @@ class random {
    * @param {*} limit
    */
   static ludOneTo (limit) {
-    return Math.exp(this.float() * Math.log(limit))
+    return Math.exp(random.float() * Math.log(limit))
   }
 
   static item (list) {
@@ -68,7 +77,7 @@ class random {
       logger.traceback()
       throw new TypeError(`random.item() received invalid object: (${list})`)
     }
-    return list[this.number(list.length)]
+    return list[random.number(list.length)]
   }
 
   /**
@@ -80,14 +89,14 @@ class random {
     for (let i in obj) {
       list.push(i)
     }
-    return this.item(list)
+    return random.item(list)
   }
 
   /**
    * Return a random Boolean value.
    */
   static bool () {
-    return this.item([true, false])
+    return random.item([true, false])
   }
 
   static pick (obj) {
@@ -95,7 +104,7 @@ class random {
       return obj()
     }
     if (Array.isArray(obj)) {
-      return this.pick(this.item(obj))
+      return random.pick(random.item(obj))
     }
     return obj
   }
@@ -108,7 +117,7 @@ class random {
       logger.traceback()
       throw new TypeError(`random.chance() received non-number type: (${limit})`)
     }
-    return this.number(limit) === 1
+    return random.number(limit) === 1
   }
 
   static choose (list, flat) {
@@ -120,13 +129,13 @@ class random {
     for (let i = 0; i < list.length; i++) {
       total += list[i][0]
     }
-    let n = this.number(total)
+    let n = random.number(total)
     for (let i = 0; i < list.length; i++) {
       if (n < list[i][0]) {
         if (flat === true) {
           return list[i][1]
         } else {
-          return this.pick([list[i][1]])
+          return random.pick([list[i][1]])
         }
       }
       n = n - list[i][0]
@@ -134,7 +143,7 @@ class random {
     if (flat === true) {
       return list[0][1]
     }
-    return this.pick([list[0][1]])
+    return random.pick([list[0][1]])
   }
 
   /**
@@ -152,13 +161,13 @@ class random {
   }
 
   static use (obj) {
-    return this.bool() ? obj : ''
+    return random.bool() ? obj : ''
   }
 
   static shuffle (arr) {
     let i = arr.length
     while (i--) {
-      let p = this.number(i + 1)
+      let p = random.number(i + 1)
       let t = arr[i]
       arr[i] = arr[p]
       arr[p] = t
@@ -167,7 +176,7 @@ class random {
 
   static shuffled (arr) {
     let newArray = arr.slice()
-    this.shuffle(newArray)
+    random.shuffle(newArray)
     return newArray
   }
 
@@ -177,11 +186,11 @@ class random {
       throw new TypeError(`random.subset() received non-array type: (${list})`)
     }
     if (typeof limit !== 'number') {
-      limit = this.number(list.length + 1)
+      limit = random.number(list.length + 1)
     }
     let result = []
     for (let i = 0; i < limit; i++) {
-      result.push(this.pick(list))
+      result.push(random.pick(list))
     }
     return result
   }
@@ -193,7 +202,7 @@ class random {
   static pop (arr) {
     let i, obj
 
-    i = this.number(arr.length)
+    i = random.number(arr.length)
     obj = arr[i]
     arr.splice(i, 1)
 
@@ -201,7 +210,7 @@ class random {
   }
 
   static hex (len) {
-    return this.number(Math.pow(2, len * 4)).toString(16)
+    return random.number(Math.pow(2, len * 4)).toString(16)
   }
 }