diff --git a/src/util/Collection.js b/src/util/Collection.js
index 5e45c968f..8477404f7 100644
--- a/src/util/Collection.js
+++ b/src/util/Collection.js
@@ -1,3 +1,5 @@
+const util = require('util');
+
 /**
  * A Map with additional utility methods. This is used throughout discord.js rather than Arrays for anything that has
  * an ID, for significantly improved performance and ease-of-use.
@@ -458,4 +460,59 @@ class Collection extends Map {
   }
 }
 
+/**
+ * Searches for all items where their specified property's value is identical to the given value
+ * (`item[prop] === value`).
+ * @param {string} prop The property to test against
+ * @param {*} value The expected value
+ * @returns {Array}
+ * @deprecated
+ * @example
+ * collection.findAll('username', 'Bob');
+ */
+Collection.prototype.findAll =
+  util.deprecate(Collection.prototype.findAll, 'Collection#findAll: use Collection#filter instead');
+
+Collection.prototype.filterArray =
+  util.deprecate(Collection.prototype.filterArray, 'Collection#filterArray: use Collection#filter instead');
+
+Collection.prototype.exists =
+  util.deprecate(Collection.prototype.exists, 'Collection#exists: use Collection#some instead');
+
+Collection.prototype.find = function find(propOrFn, value) {
+  if (typeof propOrFn === 'string') {
+    process.emitWarning('Collection#find: pass a function instead', 'DeprecationWarning');
+    if (typeof value === 'undefined') throw new Error('Value must be specified.');
+    for (const item of this.values()) {
+      if (item[propOrFn] === value) return item;
+    }
+    return null;
+  } else if (typeof propOrFn === 'function') {
+    for (const [key, val] of this) {
+      if (propOrFn(val, key, this)) return val;
+    }
+    return null;
+  } else {
+    throw new Error('First argument must be a property string or a function.');
+  }
+};
+
+Collection.prototype.findKey = function findKey(propOrFn, value) {
+  if (typeof propOrFn === 'string') {
+    process.emitWarning('Collection#findKey: pass a function instead', 'DeprecationWarning');
+    if (typeof value === 'undefined') throw new Error('Value must be specified.');
+    for (const [key, val] of this) {
+      if (val[propOrFn] === value) return key;
+    }
+    return null;
+  } else if (typeof propOrFn === 'function') {
+    for (const [key, val] of this) {
+      if (propOrFn(val, key, this)) return key;
+    }
+    return null;
+  } else {
+    throw new Error('First argument must be a property string or a function.');
+  }
+};
+
 module.exports = Collection;