diff --git a/build.gradle b/build.gradle
index 89325d4..176e6a2 100644
--- a/build.gradle
+++ b/build.gradle
@@ -8,11 +8,10 @@ buildscript {
     }
 }
 plugins {
-    id 'com.github.ben-manes.versions' version '0.14.0'
+    id 'com.github.ben-manes.versions' version '0.15.0'
 }
 
 subprojects {
-    apply plugin: 'java'
     apply plugin: 'kotlin'
     apply plugin: 'maven'
     apply plugin: 'signing'
@@ -21,6 +20,7 @@ subprojects {
     apply plugin: 'com.github.ben-manes.versions'
 
     sourceCompatibility = 1.7
+    targetCompatibility = 1.7
     group = 'ch.dissem.jabit'
 
     repositories {
@@ -28,7 +28,7 @@ subprojects {
         maven { url 'https://oss.sonatype.org/content/repositories/snapshots/' }
     }
     dependencies {
-        compile "org.jetbrains.kotlin:kotlin-stdlib-jre8:$kotlin_version"
+        compile "org.jetbrains.kotlin:kotlin-stdlib-jre7:$kotlin_version"
         compile "org.jetbrains.kotlin:kotlin-reflect:$kotlin_version"
     }
 
diff --git a/core/build.gradle b/core/build.gradle
index f43c541..ef0c51a 100644
--- a/core/build.gradle
+++ b/core/build.gradle
@@ -28,6 +28,6 @@ dependencies {
     compile 'ch.dissem.msgpack:msgpack:1.0.0'
     testCompile 'junit:junit:4.12'
     testCompile 'org.hamcrest:hamcrest-library:1.3'
-    testCompile 'com.nhaarman:mockito-kotlin:1.4.0'
+    testCompile 'com.nhaarman:mockito-kotlin:1.5.0'
     testCompile project(':cryptography-bc')
 }
diff --git a/core/src/main/kotlin/ch/dissem/bitmessage/entity/NetworkMessage.kt b/core/src/main/kotlin/ch/dissem/bitmessage/entity/NetworkMessage.kt
index d0c427a..c1a251d 100644
--- a/core/src/main/kotlin/ch/dissem/bitmessage/entity/NetworkMessage.kt
+++ b/core/src/main/kotlin/ch/dissem/bitmessage/entity/NetworkMessage.kt
@@ -40,7 +40,6 @@ data class NetworkMessage(
         return byteArrayOf(d[0], d[1], d[2], d[3])
     }
 
-    @Throws(IOException::class)
     override fun write(out: OutputStream) {
         // magic
         Encode.int32(MAGIC, out)
diff --git a/core/src/main/kotlin/ch/dissem/bitmessage/entity/Plaintext.kt b/core/src/main/kotlin/ch/dissem/bitmessage/entity/Plaintext.kt
index 3dcf0dc..9a8c90e 100644
--- a/core/src/main/kotlin/ch/dissem/bitmessage/entity/Plaintext.kt
+++ b/core/src/main/kotlin/ch/dissem/bitmessage/entity/Plaintext.kt
@@ -36,14 +36,14 @@ import java.util.*
 import java.util.Collections
 import kotlin.collections.HashSet
 
-internal fun message(encoding: Plaintext.Encoding, subject: String, body: String): ByteArray = when (encoding) {
+private fun message(encoding: Plaintext.Encoding, subject: String, body: String): ByteArray = when (encoding) {
     SIMPLE -> "Subject:$subject\nBody:$body".toByteArray()
     EXTENDED -> Message.Builder().subject(subject).body(body).build().zip()
     TRIVIAL -> (subject + body).toByteArray()
     IGNORE -> ByteArray(0)
 }
 
-internal fun ackData(type: Plaintext.Type, ackData: ByteArray?): ByteArray? {
+private fun ackData(type: Plaintext.Type, ackData: ByteArray?): ByteArray? {
     if (ackData != null) {
         return ackData
     } else if (type == MSG) {
@@ -54,7 +54,7 @@ internal fun ackData(type: Plaintext.Type, ackData: ByteArray?): ByteArray? {
 }
 
 /**
- * The unencrypted message to be sent by 'msg' or 'broadcast'.
+ * A plaintext message before encryption or after decryption.
  */
 class Plaintext private constructor(
     val type: Type,
@@ -464,7 +464,7 @@ class Plaintext private constructor(
     }
 
     fun removeLabel(type: Label.Type) {
-        labels.removeIf { it.type == type }
+        labels.removeAll { it.type == type }
     }
 
     fun isUnread(): Boolean {
diff --git a/core/src/main/kotlin/ch/dissem/bitmessage/entity/valueobject/Label.kt b/core/src/main/kotlin/ch/dissem/bitmessage/entity/valueobject/Label.kt
index 7b221df..6fd4fd6 100644
--- a/core/src/main/kotlin/ch/dissem/bitmessage/entity/valueobject/Label.kt
+++ b/core/src/main/kotlin/ch/dissem/bitmessage/entity/valueobject/Label.kt
@@ -21,11 +21,11 @@ import java.util.*
 
 data class Label(
     private val label: String,
-    val type: Label.Type?,
+    val type: Label.Type? = null,
     /**
      * RGBA representation for the color.
      */
-    var color: Int
+    var color: Int = 0
 ) : Serializable {
 
     var id: Any? = null
diff --git a/core/src/main/kotlin/ch/dissem/bitmessage/ports/AbstractCryptography.kt b/core/src/main/kotlin/ch/dissem/bitmessage/ports/AbstractCryptography.kt
index b655bd1..f6b779b 100644
--- a/core/src/main/kotlin/ch/dissem/bitmessage/ports/AbstractCryptography.kt
+++ b/core/src/main/kotlin/ch/dissem/bitmessage/ports/AbstractCryptography.kt
@@ -111,7 +111,6 @@ abstract class AbstractCryptography protected constructor(@JvmField protected va
         }
     }
 
-    @Throws(GeneralSecurityException::class)
     protected fun doSign(data: ByteArray, privKey: java.security.PrivateKey): ByteArray {
         // TODO: change this to ALGORITHM_EVP_SHA256 once it's generally used in the network
         val sig = Signature.getInstance(ALGORITHM_ECDSA_SHA1, provider)
@@ -121,7 +120,6 @@ abstract class AbstractCryptography protected constructor(@JvmField protected va
     }
 
 
-    @Throws(GeneralSecurityException::class)
     protected fun doCheckSignature(data: ByteArray, signature: ByteArray, publicKey: PublicKey): Boolean {
         for (algorithm in arrayOf(ALGORITHM_ECDSA_SHA1, ALGORITHM_EVP_SHA256)) {
             val sig = Signature.getInstance(algorithm, provider)
diff --git a/cryptography-bc/build.gradle b/cryptography-bc/build.gradle
index 9adb0b5..a1b7dff 100644
--- a/cryptography-bc/build.gradle
+++ b/cryptography-bc/build.gradle
@@ -12,8 +12,8 @@ uploadArchives {
 
 dependencies {
     compile project(':core')
-    compile 'org.bouncycastle:bcprov-jdk15on:1.56'
+    compile 'org.bouncycastle:bcprov-jdk15on:1.57'
     testCompile 'junit:junit:4.12'
-    testCompile 'org.mockito:mockito-core:2.7.21'
+    testCompile 'com.nhaarman:mockito-kotlin:1.5.0'
     testCompile project(path: ':core', configuration: 'testArtifacts')
 }
diff --git a/cryptography-sc/build.gradle b/cryptography-sc/build.gradle
index d69b841..b335a7c 100644
--- a/cryptography-sc/build.gradle
+++ b/cryptography-sc/build.gradle
@@ -12,8 +12,8 @@ uploadArchives {
 
 dependencies {
     compile project(':core')
-    compile 'com.madgag.spongycastle:prov:1.54.0.0'
+    compile 'com.madgag.spongycastle:prov:1.56.0.0'
     testCompile 'junit:junit:4.12'
-    testCompile 'org.mockito:mockito-core:2.7.21'
+    testCompile 'com.nhaarman:mockito-kotlin:1.5.0'
     testCompile project(path: ':core', configuration: 'testArtifacts')
 }
diff --git a/demo/build.gradle b/demo/build.gradle
index a00dcf4..3cda8ca 100644
--- a/demo/build.gradle
+++ b/demo/build.gradle
@@ -15,6 +15,7 @@ uploadArchives {
 }
 
 sourceCompatibility = 1.8
+targetCompatibility = 1.8
 
 test.enabled = Boolean.valueOf(systemTestsEnabled)
 
@@ -30,8 +31,8 @@ dependencies {
     compile project(':wif')
     compile 'org.slf4j:slf4j-simple:1.7.25'
     compile 'args4j:args4j:2.33'
-    compile 'com.h2database:h2:1.4.194'
-    compile 'org.apache.commons:commons-lang3:3.5'
+    compile 'com.h2database:h2:1.4.196'
+    compile 'org.apache.commons:commons-lang3:3.6'
     testCompile 'junit:junit:4.12'
-    testCompile 'com.nhaarman:mockito-kotlin:1.4.0'
+    testCompile 'com.nhaarman:mockito-kotlin:1.5.0'
 }
diff --git a/extensions/build.gradle b/extensions/build.gradle
index 1b3cc8b..188c581 100644
--- a/extensions/build.gradle
+++ b/extensions/build.gradle
@@ -30,7 +30,7 @@ dependencies {
     compile project(':core')
     testCompile 'junit:junit:4.12'
     testCompile 'org.slf4j:slf4j-simple:1.7.25'
-    testCompile 'org.mockito:mockito-core:2.7.21'
+    testCompile 'com.nhaarman:mockito-kotlin:1.5.0'
     testCompile project(path: ':core', configuration: 'testArtifacts')
     testCompile project(':cryptography-bc')
 }
diff --git a/networking/build.gradle b/networking/build.gradle
index 6ec5920..212ff46 100644
--- a/networking/build.gradle
+++ b/networking/build.gradle
@@ -14,7 +14,7 @@ dependencies {
     compile project(':core')
     testCompile 'junit:junit:4.12'
     testCompile 'org.slf4j:slf4j-simple:1.7.25'
-    testCompile 'com.nhaarman:mockito-kotlin:1.4.0'
+    testCompile 'com.nhaarman:mockito-kotlin:1.5.0'
     testCompile project(path: ':core', configuration: 'testArtifacts')
     testCompile project(':cryptography-bc')
 }
diff --git a/repositories/build.gradle b/repositories/build.gradle
index 1be3306..dfeb9ad 100644
--- a/repositories/build.gradle
+++ b/repositories/build.gradle
@@ -10,14 +10,12 @@ uploadArchives {
     }
 }
 
-sourceCompatibility = 1.8
-
 dependencies {
     compile project(':core')
-    compile 'org.flywaydb:flyway-core:4.1.2'
+    compile 'org.flywaydb:flyway-core:4.2.0'
     testCompile 'junit:junit:4.12'
-    testCompile 'com.h2database:h2:1.4.194'
-    testCompile 'com.nhaarman:mockito-kotlin:1.4.0'
+    testCompile 'com.h2database:h2:1.4.196'
+    testCompile 'com.nhaarman:mockito-kotlin:1.5.0'
     testCompile project(path: ':core', configuration: 'testArtifacts')
     testCompile project(':cryptography-bc')
 }
diff --git a/repositories/src/main/kotlin/ch/dissem/bitmessage/repository/JdbcInventory.kt b/repositories/src/main/kotlin/ch/dissem/bitmessage/repository/JdbcInventory.kt
index 637c5dd..07d8efc 100644
--- a/repositories/src/main/kotlin/ch/dissem/bitmessage/repository/JdbcInventory.kt
+++ b/repositories/src/main/kotlin/ch/dissem/bitmessage/repository/JdbcInventory.kt
@@ -156,7 +156,7 @@ class JdbcInventory(config: JdbcConfig) : JdbcHelper(config), Inventory {
         }
 
         for (c in cache.values) {
-            c.entries.removeIf { e -> e.value < now - 5 * MINUTE }
+            c.entries.removeAll { e -> e.value < now - 5 * MINUTE }
         }
     }
 
diff --git a/repositories/src/main/kotlin/ch/dissem/bitmessage/repository/JdbcMessageRepository.kt b/repositories/src/main/kotlin/ch/dissem/bitmessage/repository/JdbcMessageRepository.kt
index ad5e834..0717e8e 100644
--- a/repositories/src/main/kotlin/ch/dissem/bitmessage/repository/JdbcMessageRepository.kt
+++ b/repositories/src/main/kotlin/ch/dissem/bitmessage/repository/JdbcMessageRepository.kt
@@ -235,7 +235,6 @@ class JdbcMessageRepository(private val config: JdbcConfig) : AbstractMessageRep
         }
     }
 
-    @Throws(SQLException::class, IOException::class)
     private fun update(connection: Connection, message: Plaintext) {
         connection.prepareStatement(
             "UPDATE Message SET iv=?, type=?, sender=?, recipient=?, data=?, ack_data=?, sent=?, received=?, " +
diff --git a/wif/build.gradle b/wif/build.gradle
index cf317e5..0f2bb35 100644
--- a/wif/build.gradle
+++ b/wif/build.gradle
@@ -14,7 +14,6 @@ dependencies {
     compile project(':core')
     compile 'org.ini4j:ini4j:0.5.4'
     testCompile 'junit:junit:4.12'
-    testCompile 'org.mockito:mockito-core:2.7.21'
-    testCompile 'com.nhaarman:mockito-kotlin:1.4.0'
+    testCompile 'com.nhaarman:mockito-kotlin:1.5.0'
     testCompile project(':cryptography-bc')
 }