diff --git a/bivrost-abi-parser/build.gradle b/bivrost-abi-parser/build.gradle
index 40c42a1..652ff52 100644
--- a/bivrost-abi-parser/build.gradle
+++ b/bivrost-abi-parser/build.gradle
@@ -2,10 +2,7 @@ apply plugin: 'java'
 apply plugin: 'kotlin'
 apply plugin: 'maven'
 
-sourceCompatibility = 1.8
-
 dependencies {
-
     implementation project(':bivrost-utils')
     implementation project(':bivrost-solidity-types')
 
@@ -19,13 +16,6 @@ dependencies {
     testImplementation group: 'junit', name: 'junit', version: '4.12'
 }
 
-compileKotlin {
-    kotlinOptions.jvmTarget = "1.8"
-}
-compileTestKotlin {
-    kotlinOptions.jvmTarget = "1.8"
-}
-
 uploadArchives {
     repositories {
         mavenDeployer {
@@ -34,7 +24,7 @@ uploadArchives {
     }
 }
 
-task sourcesJar(type: Jar, dependsOn:classes) {
+task sourcesJar(type: Jar, dependsOn: classes) {
     from sourceSets.main.allSource
     classifier = 'sources'
 }
diff --git a/bivrost-abi-parser/src/main/kotlin/pm/gnosis/AbiParser.kt b/bivrost-abi-parser/src/main/kotlin/pm/gnosis/AbiParser.kt
index 805ba13..5a26077 100644
--- a/bivrost-abi-parser/src/main/kotlin/pm/gnosis/AbiParser.kt
+++ b/bivrost-abi-parser/src/main/kotlin/pm/gnosis/AbiParser.kt
@@ -5,6 +5,7 @@ import com.squareup.kotlinpoet.ParameterizedTypeName.Companion.parameterizedBy
 import com.squareup.moshi.Moshi
 import com.squareup.moshi.kotlin.reflect.KotlinJsonAdapterFactory
 import pm.gnosis.model.*
+import pm.gnosis.utils.BigIntegerUtils
 import pm.gnosis.utils.generateSolidityMethodId
 import java.io.File
 import java.math.BigInteger
@@ -268,8 +269,10 @@ object AbiParser {
         val source = if (isSolidityDynamicType(className)) {
             val dynamicValOffsetName = "$dynamicValName$DECODER_VAR_ARG_OFFSET_SUFFIX"
             function.addStatement(
-                "val·$dynamicValOffsetName·=·%T(%L.consume(),·16).intValueExact()",
-                BigInteger::class.asClassName(), DECODER_VAR_PARTITIONS_NAME
+                "val·$dynamicValOffsetName·=·%T.exact(%T(%L.consume(),·16))",
+                BigIntegerUtils::class.asClassName(),
+                BigInteger::class.asClassName(),
+                DECODER_VAR_PARTITIONS_NAME
             )
             "%L.subData(%L)" to mutableListOf(DECODER_VAR_PARTITIONS_NAME, dynamicValOffsetName)
         } else {
diff --git a/bivrost-abi-parser/src/test/resources/automatic_tests/07_function_input_output/expected/Abi7.kt b/bivrost-abi-parser/src/test/resources/automatic_tests/07_function_input_output/expected/Abi7.kt
index b6a77f6..b455dda 100644
--- a/bivrost-abi-parser/src/test/resources/automatic_tests/07_function_input_output/expected/Abi7.kt
+++ b/bivrost-abi-parser/src/test/resources/automatic_tests/07_function_input_output/expected/Abi7.kt
@@ -4,6 +4,7 @@ import java.math.BigInteger
 import kotlin.String
 import pm.gnosis.model.Solidity
 import pm.gnosis.model.SolidityBase
+import pm.gnosis.utils.BigIntegerUtils
 
 class Abi7 {
     object Function {
@@ -17,7 +18,7 @@ class Abi7 {
             val source = SolidityBase.PartitionData.of(data)
 
             // Add decoders
-            val arg0Offset = BigInteger(source.consume(), 16).intValueExact()
+            val arg0Offset = BigIntegerUtils.exact(BigInteger(source.consume(), 16))
             val arg0 = Solidity.Bytes.DECODER.decode(source.subData(arg0Offset))
 
             return Return(arg0)
diff --git a/bivrost-abi-parser/src/test/resources/automatic_tests/08_unnamed_parameters/expected/Abi8.kt b/bivrost-abi-parser/src/test/resources/automatic_tests/08_unnamed_parameters/expected/Abi8.kt
index d64661c..007e3cb 100644
--- a/bivrost-abi-parser/src/test/resources/automatic_tests/08_unnamed_parameters/expected/Abi8.kt
+++ b/bivrost-abi-parser/src/test/resources/automatic_tests/08_unnamed_parameters/expected/Abi8.kt
@@ -4,6 +4,7 @@ import java.math.BigInteger
 import kotlin.String
 import pm.gnosis.model.Solidity
 import pm.gnosis.model.SolidityBase
+import pm.gnosis.utils.BigIntegerUtils
 
 class Abi8 {
     object Function {
@@ -17,7 +18,7 @@ class Abi8 {
             val source = SolidityBase.PartitionData.of(data)
 
             // Add decoders
-            val arg0Offset = BigInteger(source.consume(), 16).intValueExact()
+            val arg0Offset = BigIntegerUtils.exact(BigInteger(source.consume(), 16))
             val arg0 = Solidity.Bytes.DECODER.decode(source.subData(arg0Offset))
 
             return Return(arg0)
diff --git a/bivrost-abi-parser/src/test/resources/automatic_tests/09_complex_arrays/expected/Abi9.kt b/bivrost-abi-parser/src/test/resources/automatic_tests/09_complex_arrays/expected/Abi9.kt
index 49ff8e5..7b75038 100644
--- a/bivrost-abi-parser/src/test/resources/automatic_tests/09_complex_arrays/expected/Abi9.kt
+++ b/bivrost-abi-parser/src/test/resources/automatic_tests/09_complex_arrays/expected/Abi9.kt
@@ -7,6 +7,7 @@ import kotlin.Boolean
 import kotlin.String
 import pm.gnosis.model.Solidity
 import pm.gnosis.model.SolidityBase
+import pm.gnosis.utils.BigIntegerUtils
 
 class Abi9 {
     object Owners {
@@ -23,7 +24,7 @@ class Abi9 {
 
             // Add decoders
             val arg0 = TupleB.DECODER.decode(source)
-            val arg1Offset = BigInteger(source.consume(), 16).intValueExact()
+            val arg1Offset = BigIntegerUtils.exact(BigInteger(source.consume(), 16))
             val arg1 = SolidityBase.Vector.Decoder(TupleB.DECODER).decode(source.subData(arg1Offset))
 
             return Return(arg0, arg1)
@@ -33,9 +34,9 @@ class Abi9 {
             val source = SolidityBase.PartitionData.of(data)
 
             // Add decoders
-            val arg0Offset = BigInteger(source.consume(), 16).intValueExact()
+            val arg0Offset = BigIntegerUtils.exact(BigInteger(source.consume(), 16))
             val arg0 = SolidityBase.Vector.Decoder(TupleA.DECODER).decode(source.subData(arg0Offset))
-            val arg1Offset = BigInteger(source.consume(), 16).intValueExact()
+            val arg1Offset = BigIntegerUtils.exact(BigInteger(source.consume(), 16))
             val arg1 = SolidityBase.Vector.Decoder(SolidityBase.Vector.Decoder(Array7.Decoder(Array5.Decoder(Solidity.UInt256.DECODER)))).decode(source.subData(arg1Offset))
 
             return Arguments(arg0, arg1)
@@ -61,7 +62,7 @@ class Abi9 {
             override fun decode(source: SolidityBase.PartitionData): TupleA {
                 val arg0 = Solidity.UInt256.DECODER.decode(source)
                 val arg1 = Solidity.UInt256.DECODER.decode(source)
-                val arg2Offset = BigInteger(source.consume(), 16).intValueExact()
+                val arg2Offset = BigIntegerUtils.exact(BigInteger(source.consume(), 16))
                 val arg2 = SolidityBase.Vector.Decoder(SolidityBase.Vector.Decoder(Array7.Decoder(Array5.Decoder(Solidity.UInt256.DECODER)))).decode(source.subData(arg2Offset))
                 return TupleA(arg0, arg1, arg2)
             }
diff --git a/bivrost-abi-parser/src/test/resources/automatic_tests/14_simple_event_dynamic_not_indexed/expected/Abi14.kt b/bivrost-abi-parser/src/test/resources/automatic_tests/14_simple_event_dynamic_not_indexed/expected/Abi14.kt
index 1dff572..e6fa78d 100644
--- a/bivrost-abi-parser/src/test/resources/automatic_tests/14_simple_event_dynamic_not_indexed/expected/Abi14.kt
+++ b/bivrost-abi-parser/src/test/resources/automatic_tests/14_simple_event_dynamic_not_indexed/expected/Abi14.kt
@@ -7,6 +7,7 @@ import kotlin.String
 import kotlin.collections.List
 import pm.gnosis.model.Solidity
 import pm.gnosis.model.SolidityBase
+import pm.gnosis.utils.BigIntegerUtils
 
 class Abi14 {
     object Events {
@@ -20,9 +21,9 @@ class Abi14 {
 
                 // Decode data
                 val source = SolidityBase.PartitionData.of(data)
-                val arg0Offset = BigInteger(source.consume(), 16).intValueExact()
+                val arg0Offset = BigIntegerUtils.exact(BigInteger(source.consume(), 16))
                 val arg0 = Solidity.Bytes.DECODER.decode(source.subData(arg0Offset))
-                val arg1Offset = BigInteger(source.consume(), 16).intValueExact()
+                val arg1Offset = BigIntegerUtils.exact(BigInteger(source.consume(), 16))
                 val arg1 = Solidity.String.DECODER.decode(source.subData(arg1Offset))
                 val arg2 = TupleA.DECODER.decode(source)
                 return Arguments(arg0, arg1, arg2)
diff --git a/bivrost-abi-parser/src/test/resources/automatic_tests/16_malformed_bytes_encoding/expected/Abi16.kt b/bivrost-abi-parser/src/test/resources/automatic_tests/16_malformed_bytes_encoding/expected/Abi16.kt
index 9cd5d16..de405a4 100644
--- a/bivrost-abi-parser/src/test/resources/automatic_tests/16_malformed_bytes_encoding/expected/Abi16.kt
+++ b/bivrost-abi-parser/src/test/resources/automatic_tests/16_malformed_bytes_encoding/expected/Abi16.kt
@@ -5,6 +5,7 @@ import kotlin.Boolean
 import kotlin.String
 import pm.gnosis.model.Solidity
 import pm.gnosis.model.SolidityBase
+import pm.gnosis.utils.BigIntegerUtils
 
 class Abi16 {
     object Malformed {
@@ -18,7 +19,7 @@ class Abi16 {
             val source = SolidityBase.PartitionData.of(data)
 
             // Add decoders
-            val arg0Offset = BigInteger(source.consume(), 16).intValueExact()
+            val arg0Offset = BigIntegerUtils.exact(BigInteger(source.consume(), 16))
             val arg0 = TupleA.DECODER.decode(source.subData(arg0Offset))
 
             return Arguments(arg0)
@@ -36,9 +37,9 @@ class Abi16 {
         class Decoder : SolidityBase.TypeDecoder<TupleA> {
             override fun isDynamic(): Boolean = true
             override fun decode(source: SolidityBase.PartitionData): TupleA {
-                val arg0Offset = BigInteger(source.consume(), 16).intValueExact()
+                val arg0Offset = BigIntegerUtils.exact(BigInteger(source.consume(), 16))
                 val arg0 = Solidity.Bytes.DECODER.decode(source.subData(arg0Offset))
-                val arg1Offset = BigInteger(source.consume(), 16).intValueExact()
+                val arg1Offset = BigIntegerUtils.exact(BigInteger(source.consume(), 16))
                 val arg1 = Solidity.String.DECODER.decode(source.subData(arg1Offset))
                 return TupleA(arg0, arg1)
             }
diff --git a/bivrost-gradle-plugin/build.gradle b/bivrost-gradle-plugin/build.gradle
index 39a614f..fb7a019 100644
--- a/bivrost-gradle-plugin/build.gradle
+++ b/bivrost-gradle-plugin/build.gradle
@@ -2,9 +2,6 @@ apply plugin: 'java-library'
 apply plugin: 'kotlin'
 apply plugin: 'maven'
 
-sourceCompatibility = JavaVersion.VERSION_1_8
-targetCompatibility = JavaVersion.VERSION_1_8
-
 dependencies {
     compileOnly gradleApi()
 
diff --git a/bivrost-solidity-types-generator/build.gradle b/bivrost-solidity-types-generator/build.gradle
index 97b89a3..08428d4 100644
--- a/bivrost-solidity-types-generator/build.gradle
+++ b/bivrost-solidity-types-generator/build.gradle
@@ -2,8 +2,6 @@ apply plugin: 'java'
 apply plugin: 'kotlin'
 apply plugin: 'maven'
 
-sourceCompatibility = 1.8
-
 task runSolidityTypeGenerator(type: JavaExec) {
     def targetProject = project.parent.childProjects.get("bivrost-solidity-types") ?: project
     def srcDirs = targetProject.sourceSets.main.kotlin.getSrcDirs()
@@ -28,14 +26,6 @@ dependencies {
     testImplementation group: 'junit', name: 'junit', version: '4.12'
 }
 
-compileKotlin {
-    kotlinOptions.jvmTarget = "1.8"
-}
-
-compileTestKotlin {
-    kotlinOptions.jvmTarget = "1.8"
-}
-
 task sourcesJar(type: Jar, dependsOn:classes) {
     from sourceSets.main.allSource
     classifier = 'sources'
diff --git a/bivrost-solidity-types/build.gradle b/bivrost-solidity-types/build.gradle
index ff7d7ca..869a77f 100644
--- a/bivrost-solidity-types/build.gradle
+++ b/bivrost-solidity-types/build.gradle
@@ -2,21 +2,12 @@ apply plugin: 'java'
 apply plugin: 'kotlin'
 apply plugin: 'maven'
 
-sourceCompatibility = 1.8
-
 dependencies {
     implementation "org.jetbrains.kotlin:kotlin-stdlib"
 
     testImplementation group: 'junit', name: 'junit', version: '4.12'
 }
 
-compileKotlin {
-    kotlinOptions.jvmTarget = "1.8"
-}
-compileTestKotlin {
-    kotlinOptions.jvmTarget = "1.8"
-}
-
 uploadArchives {
     repositories {
         mavenDeployer {
diff --git a/bivrost-solidity-types/src/main/kotlin/pm/gnosis/utils/DataTypeExtensions.kt b/bivrost-solidity-types/src/main/kotlin/pm/gnosis/utils/DataTypeExtensions.kt
index 499d101..df94e2c 100644
--- a/bivrost-solidity-types/src/main/kotlin/pm/gnosis/utils/DataTypeExtensions.kt
+++ b/bivrost-solidity-types/src/main/kotlin/pm/gnosis/utils/DataTypeExtensions.kt
@@ -1,12 +1,13 @@
 package pm.gnosis.utils
 
+import java.math.BigInteger
 import kotlin.experimental.and
 
 fun String.padStartMultiple(multiple: Int, padChar: Char = ' ') =
-        this.padStart(if (this.length % multiple != 0) this.length + multiple - this.length % multiple else 0, padChar)
+    this.padStart(if (this.length % multiple != 0) this.length + multiple - this.length % multiple else 0, padChar)
 
 fun String.padEndMultiple(multiple: Int, padChar: Char = ' ') =
-        this.padEnd(if (this.length % multiple != 0) this.length + multiple - this.length % multiple else 0, padChar)
+    this.padEnd(if (this.length % multiple != 0) this.length + multiple - this.length % multiple else 0, padChar)
 
 
 private val hexArray = "0123456789abcdef".toCharArray()
@@ -32,3 +33,10 @@ fun String.hexToByteArray(): ByteArray {
     }
     return data
 }
+
+// Compatibility method for pre Java8
+object BigIntegerUtils {
+    fun exact(bigInteger: BigInteger): Int =
+        if (bigInteger.bitLength() <= 31) bigInteger.toInt()
+        else throw ArithmeticException("BigInteger out of int range")
+}
diff --git a/bivrost-utils/build.gradle b/bivrost-utils/build.gradle
index aeda2f7..e6e99af 100644
--- a/bivrost-utils/build.gradle
+++ b/bivrost-utils/build.gradle
@@ -2,10 +2,7 @@ apply plugin: 'java'
 apply plugin: 'kotlin'
 apply plugin: 'maven'
 
-sourceCompatibility = 1.8
-
 dependencies {
-
     implementation project(':bivrost-solidity-types')
 
     implementation "org.jetbrains.kotlin:kotlin-stdlib"
@@ -16,13 +13,6 @@ dependencies {
     testImplementation group: 'junit', name: 'junit', version: '4.12'
 }
 
-compileKotlin {
-    kotlinOptions.jvmTarget = "1.8"
-}
-compileTestKotlin {
-    kotlinOptions.jvmTarget = "1.8"
-}
-
 uploadArchives {
     repositories {
         mavenDeployer {