diff --git a/build.gradle.kts b/build.gradle.kts
index c31cd40..5624237 100644
--- a/build.gradle.kts
+++ b/build.gradle.kts
@@ -16,5 +16,6 @@ repositories {
 allprojects {
     tasks.withType<KotlinCompile> {
         kotlinOptions.jvmTarget = "14"
+        kotlinOptions.freeCompilerArgs += "-progressive"
     }
 }
diff --git a/buildSrc/build.gradle.kts b/buildSrc/build.gradle.kts
index 9fa160d..6eb3e4e 100644
--- a/buildSrc/build.gradle.kts
+++ b/buildSrc/build.gradle.kts
@@ -18,10 +18,7 @@ dependencies {
 
 tasks {
     compileKotlin {
-        kotlinOptions.freeCompilerArgs = listOf(
-            "-Xopt-in=kotlin.time.ExperimentalTime",
-            "-progressive"
-        )
+        kotlinOptions.freeCompilerArgs += "-Xopt-in=kotlin.time.ExperimentalTime"
     }
 }
 
diff --git a/test-plugin/build.gradle.kts b/test-plugin/build.gradle.kts
index 1ebdc45..2e69237 100644
--- a/test-plugin/build.gradle.kts
+++ b/test-plugin/build.gradle.kts
@@ -16,9 +16,7 @@ dependencies {
 
 tasks {
     compileKotlin {
-        kotlinOptions.freeCompilerArgs = listOf(
-            "-Xopt-in=kotlin.ExperimentalUnsignedTypes"
-        )
+        kotlinOptions.freeCompilerArgs += "-Xopt-in=kotlin.ExperimentalUnsignedTypes"
     }
 
     shadowJar {
diff --git a/uranos-api/build.gradle.kts b/uranos-api/build.gradle.kts
index 54eb710..2a93ad6 100644
--- a/uranos-api/build.gradle.kts
+++ b/uranos-api/build.gradle.kts
@@ -43,11 +43,10 @@ kotlin {
 
 tasks {
     compileKotlin {
-        kotlinOptions.freeCompilerArgs = listOf(
+        kotlinOptions.freeCompilerArgs += listOf(
             "-Xopt-in=kotlin.contracts.ExperimentalContracts",
             "-Xopt-in=kotlin.ExperimentalUnsignedTypes",
-            "-Xopt-in=kotlin.RequiresOptIn",
-            "-progressive"
+            "-Xopt-in=kotlin.RequiresOptIn"
         )
     }
 
diff --git a/uranos-packet-codecs/build.gradle.kts b/uranos-packet-codecs/build.gradle.kts
index 8e7a9a3..44f4d01 100644
--- a/uranos-packet-codecs/build.gradle.kts
+++ b/uranos-packet-codecs/build.gradle.kts
@@ -28,9 +28,7 @@ dependencies {
 
 tasks {
     compileKotlin {
-        kotlinOptions.freeCompilerArgs = listOf(
-            "-Xopt-in=kotlin.RequiresOptIn"
-        )
+        kotlinOptions.freeCompilerArgs += "-Xopt-in=kotlin.RequiresOptIn"
     }
 
     test {