diff --git a/attributes-kt/api/attributes-kt.api b/attributes-kt/api/attributes-kt.api
index 26386d9d7..403e12f5c 100644
--- a/attributes-kt/api/attributes-kt.api
+++ b/attributes-kt/api/attributes-kt.api
@@ -14,12 +14,16 @@ public abstract interface class space/kscience/attributes/AttributeWithDefault :
 
 public abstract interface class space/kscience/attributes/Attributes {
 	public static final field Companion Lspace/kscience/attributes/Attributes$Companion;
+	public abstract fun equals (Ljava/lang/Object;)Z
 	public fun get (Lspace/kscience/attributes/Attribute;)Ljava/lang/Object;
 	public abstract fun getContent ()Ljava/util/Map;
 	public fun getKeys ()Ljava/util/Set;
+	public abstract fun hashCode ()I
+	public abstract fun toString ()Ljava/lang/String;
 }
 
 public final class space/kscience/attributes/Attributes$Companion {
+	public final fun equals (Lspace/kscience/attributes/Attributes;Lspace/kscience/attributes/Attributes;)Z
 	public final fun getEMPTY ()Lspace/kscience/attributes/Attributes;
 }
 
@@ -27,11 +31,14 @@ public final class space/kscience/attributes/AttributesBuilder : space/kscience/
 	public fun <init> ()V
 	public final fun add (Lspace/kscience/attributes/SetAttribute;Ljava/lang/Object;)V
 	public final fun build ()Lspace/kscience/attributes/Attributes;
+	public fun equals (Ljava/lang/Object;)Z
 	public final fun from (Lspace/kscience/attributes/Attributes;)V
 	public fun getContent ()Ljava/util/Map;
+	public fun hashCode ()I
 	public final fun invoke (Lspace/kscience/attributes/Attribute;Ljava/lang/Object;)V
 	public final fun remove (Lspace/kscience/attributes/SetAttribute;Ljava/lang/Object;)V
 	public final fun set (Lspace/kscience/attributes/Attribute;Ljava/lang/Object;)V
+	public fun toString ()Ljava/lang/String;
 }
 
 public final class space/kscience/attributes/AttributesBuilderKt {
diff --git a/build.gradle.kts b/build.gradle.kts
index 9231fc312..ec82e8eeb 100644
--- a/build.gradle.kts
+++ b/build.gradle.kts
@@ -14,7 +14,7 @@ allprojects {
     }
 
     group = "space.kscience"
-    version = "0.4.0-RC2"
+    version = "0.4.0"
 }
 
 subprojects {
@@ -69,4 +69,4 @@ ksciencePublish {
 
 apiValidation.nonPublicMarkers.add("space.kscience.kmath.UnstableKMathAPI")
 
-val multikVersion by extra("0.2.2")
+val multikVersion by extra("0.2.3")
diff --git a/buildSrc/settings.gradle.kts b/buildSrc/settings.gradle.kts
index af804cb7d..09633711e 100644
--- a/buildSrc/settings.gradle.kts
+++ b/buildSrc/settings.gradle.kts
@@ -6,7 +6,7 @@
 enableFeaturePreview("TYPESAFE_PROJECT_ACCESSORS")
 
 plugins {
-    id("org.gradle.toolchains.foojay-resolver-convention") version "0.7.0"
+    id("org.gradle.toolchains.foojay-resolver-convention") version "0.8.0"
 }
 
 dependencyResolutionManagement {