diff --git a/build.gradle.kts b/build.gradle.kts
index a365a7d30..222c69ae7 100644
--- a/build.gradle.kts
+++ b/build.gradle.kts
@@ -1,5 +1,5 @@
 plugins {
-    val kotlinVersion = "1.7.21"
+    val kotlinVersion = "1.9.0"
     id("com.android.application") version ("7.3.1") apply (false)
     id("org.jetbrains.kotlin.android") version kotlinVersion apply (false)
     id("org.jetbrains.kotlin.kapt") version kotlinVersion apply (false)
diff --git a/uhabits-android/build.gradle.kts b/uhabits-android/build.gradle.kts
index 7ef9e823b..6282e738f 100644
--- a/uhabits-android/build.gradle.kts
+++ b/uhabits-android/build.gradle.kts
@@ -81,7 +81,7 @@ android {
 
 dependencies {
     val daggerVersion = "2.46"
-    val kotlinVersion = "1.7.21"
+    val kotlinVersion = "1.9.0"
     val kxCoroutinesVersion = "1.6.4"
     val ktorVersion = "1.6.8"
     val espressoVersion = "3.5.1"
diff --git a/uhabits-server/build.gradle.kts b/uhabits-server/build.gradle.kts
index 9a59b33a8..f40b2ba0b 100644
--- a/uhabits-server/build.gradle.kts
+++ b/uhabits-server/build.gradle.kts
@@ -34,7 +34,7 @@ application {
 
 dependencies {
     val ktorVersion = "1.6.8"
-    val kotlinVersion = "1.7.21"
+    val kotlinVersion = "1.9.0"
     val logbackVersion = "1.4.5"
     implementation("org.jetbrains.kotlin:kotlin-stdlib-jdk8:$kotlinVersion")
     implementation("io.ktor:ktor-server-netty:$ktorVersion")