diff --git a/shared/build.gradle.kts b/shared/build.gradle.kts
index 31efdb8..cc5d678 100644
--- a/shared/build.gradle.kts
+++ b/shared/build.gradle.kts
@@ -6,6 +6,7 @@ plugins {
     alias(libs.plugins.kotlinMultiplatform)
     alias(libs.plugins.androidLibrary)
     id("dev.mokkery") version "2.0.0"
+    kotlin("plugin.allopen") version "2.1.10"
 }
 
 kotlin {
@@ -49,3 +50,8 @@ android {
         targetCompatibility = JavaVersion.VERSION_1_8
     }
 }
+
+allOpen {
+    annotation("com.tle.astrologylibrary.OpenForMokkery")
+    // annotations("com.another.Annotation", "com.third.Annotation")
+}
\ No newline at end of file
diff --git a/shared/src/commonMain/kotlin/com/tle/astrologylibrary/OpenForMokkery.kt b/shared/src/commonMain/kotlin/com/tle/astrologylibrary/OpenForMokkery.kt
new file mode 100644
index 0000000..f37a50d
--- /dev/null
+++ b/shared/src/commonMain/kotlin/com/tle/astrologylibrary/OpenForMokkery.kt
@@ -0,0 +1,3 @@
+package com.tle.astrologylibrary
+
+annotation class OpenForMokkery()
\ No newline at end of file