diff --git a/allure-adapter-plugin/src/main/kotlin/io/qameta/allure/gradle/adapter/AllureAdapterExtension.kt b/allure-adapter-plugin/src/main/kotlin/io/qameta/allure/gradle/adapter/AllureAdapterExtension.kt
index 3d6c292..5e31a5f 100644
--- a/allure-adapter-plugin/src/main/kotlin/io/qameta/allure/gradle/adapter/AllureAdapterExtension.kt
+++ b/allure-adapter-plugin/src/main/kotlin/io/qameta/allure/gradle/adapter/AllureAdapterExtension.kt
@@ -170,7 +170,8 @@ open class AllureAdapterExtension @Inject constructor(
             "taskName" to taskName,
             "buildName" to project.name,
             "projectPath" to project.path,
-            "projectVersion" to project.version
+            // toString is to avoid unexpected interaction of custom objects and Json serializer
+            "projectVersion" to project.version.toString()
         )
         val resultsPath = Paths.get(resultsDir.absoluteFile.path)
         Files.createDirectories(resultsPath)