diff --git a/.github/workflows/check-pr-style.yml b/.github/workflows/check-pr-style.yml
new file mode 100644
index 000000000..7ac69d24b
--- /dev/null
+++ b/.github/workflows/check-pr-style.yml
@@ -0,0 +1,31 @@
+name: Check PR code style
+
+on:
+  pull_request:
+    branches: [ master ]
+
+jobs:
+  build:
+
+    runs-on: ubuntu-latest
+
+    steps:
+    - uses: actions/checkout@v2
+    - name: Set up JDK 11
+      uses: actions/setup-java@v1
+      with:
+        java-version: 1.11
+    - name: Run java checkstyle
+      uses: nikitasavinov/checkstyle-action@d87d526a914fc5cb0b003908e35038dbb2d6e1b7
+      with:
+        # Report level for reviewdog [info,warning,error]
+        level: info
+        # Reporter of reviewdog command [github-pr-check,github-pr-review]
+        reporter: github-pr-check
+        # Filtering for the reviewdog command [added,diff_context,file,nofilter].
+        filter_mode: added
+        # Exit code for reviewdog when errors are found [true,false].
+        fail_on_error: false
+        # Checkstyle config file
+        checkstyle_config: minestom_checks.xml
+        checkstyle_version: "8.37"
diff --git a/.github/workflows/tests.yml b/.github/workflows/tests.yml
index a3cf9d6c7..c6d8bda7c 100644
--- a/.github/workflows/tests.yml
+++ b/.github/workflows/tests.yml
@@ -31,5 +31,5 @@ jobs:
           net/minestom/
     - name: Build Minestom
       run: ./gradlew classes testClasses
-    - name: Run tests
-      run: ./gradlew check
+    - name: Run Minestom tests
+      run: ./gradlew test
diff --git a/build.gradle b/build.gradle
index f84f82d6d..f01a523cc 100644
--- a/build.gradle
+++ b/build.gradle
@@ -6,6 +6,7 @@ plugins {
     id 'maven-publish'
     id 'net.ltgt.apt' version '0.10'
     id 'org.jetbrains.kotlin.jvm' version '1.4.10'
+    id 'checkstyle'
 }
 
 group 'net.minestom.server'
@@ -36,7 +37,7 @@ allprojects {
         maven { url 'https://jitpack.io' }
         maven {
             name 'sponge'
-            url 'http://repo.spongepowered.org/maven'
+            url 'https://repo.spongepowered.org/maven'
         }
     }
     javadoc {
@@ -45,6 +46,11 @@ allprojects {
             addBooleanOption('html5', true)
         }
     }
+
+    checkstyle {
+        toolVersion "8.37"
+        configFile file("${projectDir}/minestom_checks.xml")
+    }
 }
 
 sourceSets {
diff --git a/minestom_checks.xml b/minestom_checks.xml
new file mode 100644
index 000000000..eb513ae72
--- /dev/null
+++ b/minestom_checks.xml
@@ -0,0 +1,303 @@
+<?xml version="1.0"?>
+<!DOCTYPE module PUBLIC
+          "-//Checkstyle//DTD Checkstyle Configuration 1.3//EN"
+          "https://checkstyle.org/dtds/configuration_1_3.dtd">
+
+<module name = "Checker">
+
+    <property name="charset" value="UTF-8"/>
+
+    <property name="severity" value="warning"/>
+
+    <property name="fileExtensions" value="java, properties, xml"/>
+
+    <module name="SuppressWarningsFilter" />
+    <module name="SuppressionSingleFilter">
+        <property name="files" value="autogenerated"/>
+        <property name="checks" value=".*"/>
+    </module>
+
+    <!-- Excludes all 'module-info.java' files              -->
+    <!-- See https://checkstyle.org/config_filefilters.html -->
+    <module name="BeforeExecutionExclusionFileFilter">
+        <property name="fileNamePattern" value="module\-info\.java$"/>
+    </module>
+    <!-- Checks for whitespace                               -->
+    <!-- See http://checkstyle.sf.net/config_whitespace.html -->
+    <module name="FileTabCharacter">
+        <property name="eachLine" value="true"/>
+    </module>
+
+    <!-- Checks whether files end with a new line.                        -->
+    <!-- See https://checkstyle.org/config_misc.html#NewlineAtEndOfFile -->
+    <module name="NewlineAtEndOfFile"/>
+
+    <!-- Miscellaneous other checks.                   -->
+    <!-- See https://checkstyle.org/config_misc.html -->
+    <module name="RegexpSingleline">
+        <property name="format" value="\s+$"/>
+        <property name="minimum" value="0"/>
+        <property name="maximum" value="0"/>
+        <property name="message" value="Line has trailing spaces."/>
+    </module>
+
+    <module name="LineLength">
+        <property name="fileExtensions" value="java"/>
+        <property name="max" value="120"/>
+        <property name="ignorePattern" value="^package.*|^import.*|^ *\* *.+$|a href|href|http://|https://|ftp://"/>
+    </module>
+
+    <module name="TreeWalker">
+
+        <module name="SuppressWarningsHolder" />
+        <module name="SuppressionCommentFilter">
+            <property name="onCommentFormat" value="\@formatter\:on" />
+            <property name="offCommentFormat" value="\@formatter\:off" />
+        </module>
+
+        <module name="OuterTypeFilename"/>
+        <module name="IllegalTokenText">
+            <property name="tokens" value="STRING_LITERAL, CHAR_LITERAL"/>
+            <property name="format"
+             value="\\u00(09|0(a|A)|0(c|C)|0(d|D)|22|27|5(C|c))|\\(0(10|11|12|14|15|42|47)|134)"/>
+            <property name="message"
+             value="Consider using special escape sequence instead of octal value or Unicode escaped value."/>
+        </module>
+        <module name="AvoidEscapedUnicodeCharacters">
+            <property name="allowEscapesForControlCharacters" value="true"/>
+            <property name="allowByTailComment" value="true"/>
+            <property name="allowNonPrintableEscapes" value="true"/>
+        </module>
+
+        <!-- Checks for imports                              -->
+        <!-- See https://checkstyle.org/config_import.html -->
+        <module name="AvoidStarImport"/>
+        <module name="IllegalImport"/> <!-- defaults to sun.* packages -->
+        <module name="RedundantImport"/>
+        <module name="UnusedImports">
+            <property name="processJavadoc" value="true"/>
+        </module>
+        <module name="CustomImportOrder">
+            <property name="sortImportsInGroupAlphabetically" value="true"/>
+            <property name="separateLineBetweenGroups" value="true"/>
+            <property name="customImportOrderRules" value="STATIC###THIRD_PARTY_PACKAGE"/>
+        </module>
+
+        <!-- Modifier Checks                                    -->
+        <!-- See https://checkstyle.org/config_modifiers.html -->
+        <module name="ModifierOrder"/>
+        <module name="RedundantModifier"/>
+
+        <module name="FinalClass"/>
+        <module name="TodoComment">
+            <property name="severity" value="info" />
+            <property name="format" value="(TODO)|(FIXME)"/>
+        </module>
+
+        <module name="OneTopLevelClass"/>
+        <module name="NoLineWrap"/>
+        <module name="EmptyBlock">
+            <property name="option" value="TEXT"/>
+            <property name="tokens"
+             value="LITERAL_TRY, LITERAL_FINALLY, LITERAL_IF, LITERAL_ELSE, LITERAL_SWITCH"/>
+        </module>
+        <module name="NeedBraces"/>
+        <module name="LeftCurly"/>
+        <module name="RightCurly">
+            <property name="id" value="RightCurlySame"/>
+            <property name="tokens"
+             value="LITERAL_TRY, LITERAL_CATCH, LITERAL_FINALLY, LITERAL_IF, LITERAL_ELSE,
+                    LITERAL_DO"/>
+        </module>
+        <module name="RightCurly">
+            <property name="id" value="RightCurlyAlone"/>
+            <property name="option" value="alone"/>
+            <property name="tokens"
+             value="CLASS_DEF, METHOD_DEF, CTOR_DEF, LITERAL_FOR, LITERAL_WHILE, STATIC_INIT,
+                    INSTANCE_INIT"/>
+        </module>
+        <module name="WhitespaceAround">
+            <property name="allowEmptyConstructors" value="true"/>
+            <property name="allowEmptyLambdas" value="true"/>
+            <property name="allowEmptyMethods" value="true"/>
+            <property name="allowEmptyTypes" value="true"/>
+            <property name="allowEmptyLoops" value="true"/>
+            <message key="ws.notFollowed"
+             value="WhitespaceAround: ''{0}'' is not followed by whitespace. Empty blocks may only be represented as '{}' when not part of a multi-block statement (4.1.3)"/>
+            <message key="ws.notPreceded"
+             value="WhitespaceAround: ''{0}'' is not preceded with whitespace."/>
+        </module>
+        <module name="OneStatementPerLine"/>
+        <module name="MultipleVariableDeclarations"/>
+        <module name="ArrayTypeStyle"/>
+        <module name="MissingSwitchDefault"/>
+        <module name="FallThrough"/>
+        <module name="UpperEll"/>
+        <module name="EmptyLineSeparator">
+            <property name="allowNoEmptyLineBetweenFields" value="true"/>
+        </module>
+        <module name="SeparatorWrap">
+            <property name="id" value="SeparatorWrapDot"/>
+            <property name="tokens" value="DOT"/>
+            <property name="option" value="nl"/>
+        </module>
+        <module name="SeparatorWrap">
+            <property name="id" value="SeparatorWrapComma"/>
+            <property name="tokens" value="COMMA"/>
+            <property name="option" value="EOL"/>
+        </module>
+        <module name="SeparatorWrap">
+            <!-- ELLIPSIS is EOL until https://github.com/google/styleguide/issues/258 -->
+            <property name="id" value="SeparatorWrapEllipsis"/>
+            <property name="tokens" value="ELLIPSIS"/>
+            <property name="option" value="EOL"/>
+        </module>
+        <module name="SeparatorWrap">
+            <!-- ARRAY_DECLARATOR is EOL until https://github.com/google/styleguide/issues/259 -->
+            <property name="id" value="SeparatorWrapArrayDeclarator"/>
+            <property name="tokens" value="ARRAY_DECLARATOR"/>
+            <property name="option" value="EOL"/>
+        </module>
+        <module name="SeparatorWrap">
+            <property name="id" value="SeparatorWrapMethodRef"/>
+            <property name="tokens" value="METHOD_REF"/>
+            <property name="option" value="nl"/>
+        </module>
+        <module name="PackageName">
+            <property name="format" value="^[a-z]+(\.[a-z][a-z0-9]*)*$"/>
+            <message key="name.invalidPattern"
+             value="Package name ''{0}'' must match pattern ''{1}''."/>
+        </module>
+        <module name="TypeName">
+            <message key="name.invalidPattern"
+             value="Type name ''{0}'' must match pattern ''{1}''."/>
+        </module>
+        <module name="MemberName">
+            <property name="format" value="^[a-z][a-z0-9][a-zA-Z0-9]*$"/>
+            <message key="name.invalidPattern"
+             value="Member name ''{0}'' must match pattern ''{1}''."/>
+        </module>
+        <module name="ParameterName">
+            <property name="format" value="^[a-z]([a-z0-9][a-zA-Z0-9]*)?$"/>
+            <message key="name.invalidPattern"
+             value="Parameter name ''{0}'' must match pattern ''{1}''."/>
+        </module>
+        <module name="LambdaParameterName">
+            <property name="format" value="^[a-z]([a-z0-9][a-zA-Z0-9]*)?$"/>
+            <message key="name.invalidPattern"
+                     value="Lambda parameter name ''{0}'' must match pattern ''{1}''."/>
+        </module>
+        <module name="CatchParameterName">
+            <property name="format" value="^[a-z]([a-z0-9][a-zA-Z0-9]*)?$"/>
+            <message key="name.invalidPattern"
+             value="Catch parameter name ''{0}'' must match pattern ''{1}''."/>
+        </module>
+        <module name="LocalVariableName">
+            <property name="tokens" value="VARIABLE_DEF"/>
+            <property name="format" value="^[a-z]([a-z0-9][a-zA-Z0-9]*)?$"/>
+            <message key="name.invalidPattern"
+             value="Local variable name ''{0}'' must match pattern ''{1}''."/>
+        </module>
+        <module name="ClassTypeParameterName">
+            <property name="format" value="(^[A-Z][0-9]?)$|([A-Z][a-zA-Z0-9]*[T]$)"/>
+            <message key="name.invalidPattern"
+             value="Class type name ''{0}'' must match pattern ''{1}''."/>
+        </module>
+        <module name="MethodTypeParameterName">
+            <property name="format" value="(^[A-Z][0-9]?)$|([A-Z][a-zA-Z0-9]*[T]$)"/>
+            <message key="name.invalidPattern"
+             value="Method type name ''{0}'' must match pattern ''{1}''."/>
+        </module>
+        <module name="InterfaceTypeParameterName">
+            <property name="format" value="(^[A-Z][0-9]?)$|([A-Z][a-zA-Z0-9]*[T]$)"/>
+            <message key="name.invalidPattern"
+             value="Interface type name ''{0}'' must match pattern ''{1}''."/>
+        </module>
+        <module name="NoFinalizer"/>
+        <module name="GenericWhitespace">
+            <message key="ws.followed"
+             value="GenericWhitespace ''{0}'' is followed by whitespace."/>
+            <message key="ws.preceded"
+             value="GenericWhitespace ''{0}'' is preceded with whitespace."/>
+            <message key="ws.illegalFollow"
+             value="GenericWhitespace ''{0}'' should followed by whitespace."/>
+            <message key="ws.notPreceded"
+             value="GenericWhitespace ''{0}'' is not preceded with whitespace."/>
+        </module>
+        <module name="Indentation">
+            <property name="basicOffset" value="4"/>
+            <property name="braceAdjustment" value="0"/>
+            <property name="caseIndent" value="4"/>
+            <property name="throwsIndent" value="8"/>
+            <property name="lineWrappingIndentation" value="8"/>
+            <property name="arrayInitIndent" value="4"/>
+        </module>
+        <module name="AbbreviationAsWordInName">
+            <property name="ignoreFinal" value="false"/>
+            <property name="allowedAbbreviationLength" value="1"/>
+        </module>
+        <module name="OverloadMethodsDeclarationOrder"/>
+        <module name="VariableDeclarationUsageDistance"/>
+        <module name="MethodParamPad"/>
+        <module name="NoWhitespaceBefore">
+            <property name="tokens"
+             value="COMMA, SEMI, POST_INC, POST_DEC, DOT, ELLIPSIS, METHOD_REF"/>
+            <property name="allowLineBreaks" value="true"/>
+        </module>
+        <module name="ParenPad"/>
+        <module name="OperatorWrap">
+            <property name="option" value="NL"/>
+            <property name="tokens"
+             value="BAND, BOR, BSR, BXOR, DIV, EQUAL, GE, GT, LAND, LE, LITERAL_INSTANCEOF, LOR,
+                    LT, MINUS, MOD, NOT_EQUAL, PLUS, QUESTION, SL, SR, STAR, METHOD_REF "/>
+        </module>
+        <module name="AnnotationLocation">
+            <property name="id" value="AnnotationLocationMostCases"/>
+            <property name="tokens"
+             value="CLASS_DEF, INTERFACE_DEF, ENUM_DEF, METHOD_DEF, CTOR_DEF"/>
+        </module>
+        <module name="AnnotationLocation">
+            <property name="id" value="AnnotationLocationVariables"/>
+            <property name="tokens" value="VARIABLE_DEF"/>
+            <property name="allowSamelineMultipleAnnotations" value="true"/>
+        </module>
+        <module name="NonEmptyAtclauseDescription"/>
+        <module name="InvalidJavadocPosition"/>
+        <module name="JavadocTagContinuationIndentation" />
+        <module name="SummaryJavadoc">
+            <property name="forbiddenSummaryFragments"
+             value="^@return the *|^This method returns |^A [{]@code [a-zA-Z0-9]+[}]( is a )"/>
+        </module>
+        <module name="JavadocParagraph">
+            <property name="allowNewlineParagraph" value="false" />
+        </module>
+        <module name="AtclauseOrder">
+            <property name="tagOrder" value="@param, @return, @throws, @deprecated"/>
+            <property name="target"
+             value="CLASS_DEF, INTERFACE_DEF, ENUM_DEF, METHOD_DEF, CTOR_DEF, VARIABLE_DEF"/>
+        </module>
+        <module name="JavadocMethod">
+            <property name="scope" value="public"/>
+            <property name="allowMissingParamTags" value="true"/>
+            <property name="allowMissingReturnTag" value="true"/>
+            <property name="allowedAnnotations" value="Override, Test"/>
+        </module>
+        <module name="MissingJavadocMethod">
+            <property name="scope" value="public"/>
+            <property name="minLineCount" value="2"/>
+            <property name="allowedAnnotations" value="Override, Test"/>
+        </module>
+        <module name="MethodName">
+            <property name="format" value="^[a-z][a-z0-9][a-zA-Z0-9_]*$"/>
+            <message key="name.invalidPattern"
+             value="Method name ''{0}'' must match pattern ''{1}''."/>
+        </module>
+        <module name="SingleLineJavadoc">
+            <property name="ignoreInlineTags" value="false"/>
+        </module>
+        <module name="EmptyCatchBlock">
+            <property name="exceptionVariableName" value="expected"/>
+        </module>
+        <module name="CommentsIndentation"/>
+    </module>
+</module>
diff --git a/src/main/java/net/minestom/server/entity/Player.java b/src/main/java/net/minestom/server/entity/Player.java
index b26b531e6..cceb40ecd 100644
--- a/src/main/java/net/minestom/server/entity/Player.java
+++ b/src/main/java/net/minestom/server/entity/Player.java
@@ -1163,8 +1163,7 @@ public class Player extends LivingEntity implements CommandSender {
     /**
      * Gets the player display name in the tab-list.
      *
-     * @return the player display name,
-     * null means that {@link #getUsername()} is displayed
+     * @return the player display name, null means that {@link #getUsername()} is displayed
      */
     @Nullable
     public ColoredText getDisplayName() {