diff --git a/i18n-sy/build.gradle.kts b/i18n-sy/build.gradle.kts
index bf3cac6a8..a16ccb73d 100644
--- a/i18n-sy/build.gradle.kts
+++ b/i18n-sy/build.gradle.kts
@@ -37,3 +37,9 @@ multiplatformResources {
     multiplatformResourcesClassName = "SYMR"
     multiplatformResourcesPackage = "tachiyomi.i18n.sy"
 }
+
+tasks.withType<org.jetbrains.kotlin.gradle.tasks.KotlinCompile> {
+    kotlinOptions.freeCompilerArgs += listOf(
+        "-Xexpect-actual-classes",
+    )
+}
diff --git a/i18n/build.gradle.kts b/i18n/build.gradle.kts
index 8a4a894ef..b7a112ce1 100644
--- a/i18n/build.gradle.kts
+++ b/i18n/build.gradle.kts
@@ -39,8 +39,13 @@ multiplatformResources {
 
 tasks {
     val localesConfigTask = registerLocalesConfigTask(project)
-
     preBuild {
         dependsOn(localesConfigTask)
     }
+
+    withType<org.jetbrains.kotlin.gradle.tasks.KotlinCompile> {
+        kotlinOptions.freeCompilerArgs += listOf(
+            "-Xexpect-actual-classes",
+        )
+    }
 }
diff --git a/source-api/build.gradle.kts b/source-api/build.gradle.kts
index 2e2f34e23..d18432a0c 100644
--- a/source-api/build.gradle.kts
+++ b/source-api/build.gradle.kts
@@ -41,3 +41,11 @@ android {
         consumerProguardFile("consumer-proguard.pro")
     }
 }
+
+tasks {
+    withType<org.jetbrains.kotlin.gradle.tasks.KotlinCompile> {
+        kotlinOptions.freeCompilerArgs += listOf(
+            "-Xexpect-actual-classes",
+        )
+    }
+}
diff --git a/source-local/build.gradle.kts b/source-local/build.gradle.kts
index 7ff24db0f..81552c61b 100644
--- a/source-local/build.gradle.kts
+++ b/source-local/build.gradle.kts
@@ -47,6 +47,7 @@ android {
 tasks {
     withType<org.jetbrains.kotlin.gradle.tasks.KotlinCompile> {
         kotlinOptions.freeCompilerArgs += listOf(
+            "-Xexpect-actual-classes",
             "-opt-in=kotlinx.serialization.ExperimentalSerializationApi",
         )
     }