diff --git a/CHANGELOG.md b/CHANGELOG.md
index 8ab88c5..d469aec 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -1,3 +1,9 @@
+# Unreleased
+
+### 🚀 New Feature
+
+- When autocompleting a username argument of a command, only usernames will now be suggested ([#32](https://github.com/HiDeoo/YaTA/pull/32) - [nD00rn](https://github.com/nD00rn)).
+
 # 1.11.0
 
 ### 🚀 New Feature
diff --git a/package.json b/package.json
index 5686765..129487a 100644
--- a/package.json
+++ b/package.json
@@ -118,6 +118,8 @@
   "bugs": {
     "url": "https://github.com/HiDeoo/YaTA/issues"
   },
-  "contributors": [],
+  "contributors": [
+    "nDoorn <ndoorn@outlook.com>"
+  ],
   "homepage": "https://yata.now.sh"
 }
diff --git a/src/components/Input.tsx b/src/components/Input.tsx
index ea54590..1b2627b 100644
--- a/src/components/Input.tsx
+++ b/src/components/Input.tsx
@@ -352,7 +352,7 @@ export default class Input extends React.Component<Props, State> {
 
           this.completions = this.props.getCompletions(
             word,
-            previousCharacter === '@',
+            previousCharacter === '@' || Command.isUsernameCompletableCommandArgument(text, cursor),
             start === 1 && Command.isCommand(previousCharacter)
           )
         }
diff --git a/src/constants/command.ts b/src/constants/command.ts
index ab0e7a0..e21bbb5 100644
--- a/src/constants/command.ts
+++ b/src/constants/command.ts
@@ -161,7 +161,7 @@ export type CommandDescriptor = {
 /**
  * A command argument.
  */
-type CommandArgument = {
+export type CommandArgument = {
   name: string
   optional?: boolean
 }
diff --git a/src/libs/Command.ts b/src/libs/Command.ts
index 538ca0f..542c189 100644
--- a/src/libs/Command.ts
+++ b/src/libs/Command.ts
@@ -1,6 +1,6 @@
 import * as _ from 'lodash'
 
-import { CommandDescriptor, CommandName, Commands } from 'Constants/command'
+import { CommandArgument, CommandDescriptor, CommandName, Commands } from 'Constants/command'
 import Notice from 'Libs/Notice'
 import { SerializedRoomState } from 'Libs/RoomState'
 import Twitch from 'Libs/Twitch'
@@ -44,6 +44,57 @@ export default class Command {
     return /^[\/|.]help(?:$|\s)/i.test(message)
   }
 
+  /**
+   * Checks if the cursor in a message is associated to a command username auto-completable argument.
+   * Note: at the moment, it is assumed that all commands having a username completable argument have that argument at
+   * the first position.
+   * @param  message - The message.
+   * @param  cursor - The cursor position.
+   * @return `true` when the cursor is matching a username completable argument.
+   */
+  public static isUsernameCompletableCommandArgument(message: string, cursor: number) {
+    // Bail out if the message is not even a command.
+    if (!Command.isCommand(message)) {
+      return false
+    }
+
+    // Grab the command name and the first argument.
+    const words = message.split(' ')
+    const commandName = words[0].substr(1)
+    const firstArgument = words[1]
+
+    // If we don't have a first argument yet, bail out.
+    if (_.isNil(firstArgument)) {
+      return false
+    }
+
+    const firstArgumentStart = commandName.length + 2
+    const firstArgumentEnd = firstArgumentStart + firstArgument.length
+
+    // If we're not auto-completing the first agument, bail out.
+    if (cursor < firstArgumentStart || cursor > firstArgumentEnd) {
+      return false
+    }
+
+    // Get the descriptor for this command.
+    const descriptor = Command.getDescriptor(commandName)
+
+    // If we can't get a valid descriptor, this means the command is unknown.
+    if (_.isNil(descriptor.name)) {
+      return false
+    }
+
+    const firstArgumentDescriptor = _.get(descriptor, 'arguments[0]') as Optional<CommandArgument>
+
+    // If the command doesn't accept any argument or the first argument is not a
+    // username, bail out.
+    if (_.isNil(firstArgumentDescriptor) || firstArgumentDescriptor.name !== 'username') {
+      return false
+    }
+
+    return true
+  }
+
   /**
    * Parses a message as a whisper command (/w user message).
    * @return The whisper details.