diff --git a/build.gradle.kts b/build.gradle.kts
index 651afb945..3c5208cf6 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 "7.4.2" 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 912b5eb68..4eac0f528 100644
--- a/uhabits-android/build.gradle.kts
+++ b/uhabits-android/build.gradle.kts
@@ -80,7 +80,7 @@ android {
 
 dependencies {
     val daggerVersion = "2.46"
-    val kotlinVersion = "1.7.21"
+    val kotlinVersion = "1.9.0"
     val kxCoroutinesVersion = "1.7.3"
     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 a96d02131..382669fd8 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")