diff --git a/config/checkstyle/checkstyle.xml b/config/checkstyle/checkstyle.xml
new file mode 100644
index 0000000000000000000000000000000000000000..b5efe8802f0d9028bf87c65ca55b2ae35bdf177f
--- /dev/null
+++ b/config/checkstyle/checkstyle.xml
@@ -0,0 +1,18 @@
+<!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"/>
+  <module name="LineLength">
+    <property name="fileExtensions" value="java"/>
+    <property name="max" value="100"/>
+    <property name="ignorePattern" value="^package.*|^import.*|a href|href|http://|https://|ftp://"/>
+  </module>
+  <module name="TreeWalker">
+    <module name="RegexpSinglelineJava">
+      <property name="format" value="^\t* +\t*\S"/>
+      <property name="message" value="Line has leading space characters; indentation should be performed with tabs only."/>
+      <property name="ignoreComments" value="true"/>
+    </module>
+  </module>
+</module>
diff --git a/dont-kill-me-lib/build.gradle b/dont-kill-me-lib/build.gradle
index e882c0bf7c18ed4f0b3021734f4a412c1915afc5..a2af387ec7b45b10a1e3f5b195a9d4c0b77e8fc1 100644
--- a/dont-kill-me-lib/build.gradle
+++ b/dont-kill-me-lib/build.gradle
@@ -1,5 +1,6 @@
 plugins {
     id 'com.android.library'
+    id 'checkstyle'
 }
 
 android {
diff --git a/mailbox-android/build.gradle b/mailbox-android/build.gradle
index 7011bc02761f4b08045966a662fb7f8bc0bab740..3f05d842718448e51919a8c40a858f594660cdcd 100644
--- a/mailbox-android/build.gradle
+++ b/mailbox-android/build.gradle
@@ -6,6 +6,7 @@ plugins {
     id 'kotlin-kapt'
     id 'dagger.hilt.android.plugin'
     id "org.jlleitschuh.gradle.ktlint" version "$ktlint_plugin_version"
+    id 'checkstyle'
 }
 
 android {
diff --git a/mailbox-cli/build.gradle b/mailbox-cli/build.gradle
index 1aade2c8a2c6f24eb08a41a34c3de81783f95559..51a8dfb078c35023282fc4bbf4fb6a3c87cc794e 100644
--- a/mailbox-cli/build.gradle
+++ b/mailbox-cli/build.gradle
@@ -4,6 +4,7 @@ plugins {
     id 'org.jetbrains.kotlin.jvm'
     id 'org.jetbrains.kotlin.kapt'
     id "org.jlleitschuh.gradle.ktlint" version "$ktlint_plugin_version"
+    id 'checkstyle'
 }
 
 sourceCompatibility = 1.8
diff --git a/mailbox-core/build.gradle b/mailbox-core/build.gradle
index 7d4568cd69a806bef811c46100ca126db6a57f0c..a7db1b0abe8a16ec6e1b2fbdad818edb304c3506 100644
--- a/mailbox-core/build.gradle
+++ b/mailbox-core/build.gradle
@@ -4,6 +4,7 @@ plugins {
     id 'org.jetbrains.kotlin.jvm'
     id 'org.jetbrains.kotlin.kapt'
     id "org.jlleitschuh.gradle.ktlint" version "$ktlint_plugin_version"
+    id 'checkstyle'
 }
 
 sourceCompatibility = 1.8