diff --git a/gradle/wrapper/gradle-wrapper.properties b/gradle/wrapper/gradle-wrapper.properties
index f371643ee..442d9132e 100644
--- a/gradle/wrapper/gradle-wrapper.properties
+++ b/gradle/wrapper/gradle-wrapper.properties
@@ -1,5 +1,5 @@
 distributionBase=GRADLE_USER_HOME
 distributionPath=wrapper/dists
-distributionUrl=https\://services.gradle.org/distributions/gradle-7.0-bin.zip
+distributionUrl=https\://services.gradle.org/distributions/gradle-6.8.3-bin.zip
 zipStoreBase=GRADLE_USER_HOME
 zipStorePath=wrapper/dists
diff --git a/kmath-stat/src/jvmTest/kotlin/space/kscience/kmath/stat/CommonsDistributionsTest.kt b/kmath-stat/src/jvmTest/kotlin/space/kscience/kmath/stat/CommonsDistributionsTest.kt
index 976020f08..dca0242fc 100644
--- a/kmath-stat/src/jvmTest/kotlin/space/kscience/kmath/stat/CommonsDistributionsTest.kt
+++ b/kmath-stat/src/jvmTest/kotlin/space/kscience/kmath/stat/CommonsDistributionsTest.kt
@@ -13,7 +13,7 @@ internal class CommonsDistributionsTest {
     fun testNormalDistributionSuspend() = runBlocking {
         val distribution = GaussianSampler(7.0, 2.0)
         val generator = RandomGenerator.default(1)
-        val sample = distribution.sample(generator).take(1000).toList().asBuffer()
+        val sample = distribution.sample(generator).take(1000).toList().toDoubleArray().asBuffer()
         Assertions.assertEquals(7.0, Mean.double(sample), 0.2)
     }
 
diff --git a/settings.gradle.kts b/settings.gradle.kts
index e419ac0e2..1f62b1388 100644
--- a/settings.gradle.kts
+++ b/settings.gradle.kts
@@ -17,6 +17,7 @@ pluginManagement {
         id("ru.mipt.npm.gradle.jvm") version toolsVersion
         id("ru.mipt.npm.gradle.publish") version toolsVersion
         kotlin("jvm") version kotlinVersion
+        kotlin("multiplatform") version kotlinVersion
         kotlin("plugin.allopen") version kotlinVersion
     }
 }