diff --git a/build.gradle.kts b/build.gradle.kts
index 8b8f5c5..0f1f342 100644
--- a/build.gradle.kts
+++ b/build.gradle.kts
@@ -6,7 +6,7 @@ plugins {
 }
 
 group = "nl.astraeus"
-version = "0.2.0-SNAPSHOT"
+version = "0.2.1-SNAPSHOT"
 
 repositories {
     mavenCentral()
diff --git a/src/commonMain/kotlin/nl/astraeus/tba/ByteArrayDefinition.kt b/src/commonMain/kotlin/nl/astraeus/tba/ByteArrayDefinition.kt
index d3535b5..10a0510 100644
--- a/src/commonMain/kotlin/nl/astraeus/tba/ByteArrayDefinition.kt
+++ b/src/commonMain/kotlin/nl/astraeus/tba/ByteArrayDefinition.kt
@@ -12,7 +12,7 @@ enum class DataType(
   DOUBLE(8),
   STRING(-1, 2),
   CLOB(-1, 4),
-  BLOB(-1, 4),
+  BLOB(-2, 0),
   ;
 }
 
diff --git a/src/commonMain/kotlin/nl/astraeus/tba/ByteArrayHandler.kt b/src/commonMain/kotlin/nl/astraeus/tba/ByteArrayHandler.kt
index 6df4d5e..f748ad7 100644
--- a/src/commonMain/kotlin/nl/astraeus/tba/ByteArrayHandler.kt
+++ b/src/commonMain/kotlin/nl/astraeus/tba/ByteArrayHandler.kt
@@ -25,21 +25,23 @@ class MutableByteArrayHandler(
   fun setFloat(index: Int, value: Float) = buffer.setFloat(index, value)
   fun setDouble(index: Int, value: Double) = buffer.setDouble(index, value)
 
-  fun setString(index: Int, value: String) {
+  fun setString(index: Int, value: String, maxLength: Int) {
     val bytes = value.encodeToByteArray()
+    check(bytes.size + 2 <= maxLength) { "String is too long" }
     buffer.setShort(index, bytes.size.toShort())
-    buffer.setBlob(index + 2, SlicedByteArray.wrap(bytes))
+    buffer.setBlob(index + 2, SlicedByteArray.wrap(bytes), maxLength - 2)
   }
 
-  fun setClob(index: Int, value: String) {
+  fun setClob(index: Int, value: String, maxLength: Int) {
     val bytes = value.encodeToByteArray()
+    check(bytes.size + 4 <= maxLength) { "Clob is too long" }
     buffer.setInt(index, bytes.size)
-    buffer.setBlob(index + 4, SlicedByteArray.wrap(bytes))
+    buffer.setBlob(index + 4, SlicedByteArray.wrap(bytes), maxLength - 4)
   }
 
-  fun setBlob(index: Int, bytes: SlicedByteArray) {
-    buffer.setInt(index, bytes.length)
-    buffer.setBlob(index + 4, bytes)
+  fun setBlob(index: Int, bytes: SlicedByteArray, maxLength: Int) {
+    check(bytes.size <= maxLength) { "Blob is too long" }
+    buffer.setBlob(index, bytes, maxLength)
   }
 }
 
@@ -87,9 +89,8 @@ open class ByteArrayHandler(
     return bytes.decodeToString()
   }
 
-  fun getBlob(index: Int): SlicedByteArray {
-    val length = buffer.getInt(index)
-    return buffer.getBlob(index + 4, length)
+  fun getBlob(index: Int, length: Int): SlicedByteArray {
+    return buffer.getBlob(index, length)
   }
 
   fun slice(range: IntRange): ByteArrayHandler {
diff --git a/src/commonMain/kotlin/nl/astraeus/tba/ByteArrayProperties.kt b/src/commonMain/kotlin/nl/astraeus/tba/ByteArrayProperties.kt
index ca9569f..516c0a5 100644
--- a/src/commonMain/kotlin/nl/astraeus/tba/ByteArrayProperties.kt
+++ b/src/commonMain/kotlin/nl/astraeus/tba/ByteArrayProperties.kt
@@ -6,7 +6,7 @@ import kotlin.reflect.KProperty
 abstract class ByteArrayProperty<T>(
   val name: String
 ) : ReadWriteProperty<TypedByteArray, T> {
-  var index: Int? = null
+  private var index: Int? = null
 
   protected fun getIndex(thisRef: TypedByteArray): Int {
     if (index == null) {
@@ -16,6 +16,22 @@ abstract class ByteArrayProperty<T>(
   }
 }
 
+abstract class ByteArrayPropertyWithLength<T>(
+  name: String
+) : ByteArrayProperty<T>(name) {
+  private var maxLength: Int? = null
+
+  protected fun getMaxLength(thisRef: TypedByteArray): Int {
+    if (maxLength == null) {
+      val type = thisRef.typeMap[name] ?: throw IllegalArgumentException(
+        "Type $name not found in typemap in $thisRef"
+      )
+      maxLength = type.size
+    }
+    return maxLength!!
+  }
+}
+
 class BooleanProperty(
   name: String
 ) : ByteArrayProperty<Boolean>(name) {
@@ -102,20 +118,20 @@ class DoubleProperty(
 
 class StringProperty(
   name: String,
-) : ByteArrayProperty<String>(name) {
+) : ByteArrayPropertyWithLength<String>(name) {
 
   override fun getValue(thisRef: TypedByteArray, property: KProperty<*>): String {
     return thisRef.data.getString(getIndex(thisRef))
   }
 
   override fun setValue(thisRef: TypedByteArray, property: KProperty<*>, value: String) {
-    thisRef.data.setString(getIndex(thisRef), value)
+    thisRef.data.setString(getIndex(thisRef), value, getMaxLength(thisRef))
   }
 }
 
 class CachedStringProperty(
   name: String,
-) : ByteArrayProperty<String>(name) {
+) : ByteArrayPropertyWithLength<String>(name) {
   var cachedValue: String? = null
 
   override fun getValue(thisRef: TypedByteArray, property: KProperty<*>): String {
@@ -126,33 +142,34 @@ class CachedStringProperty(
   }
 
   override fun setValue(thisRef: TypedByteArray, property: KProperty<*>, value: String) {
-    thisRef.data.setString(getIndex(thisRef), value)
+    thisRef.data.setString(getIndex(thisRef), value, getMaxLength(thisRef))
     cachedValue = value
   }
 }
 
 class ClobProperty(
   name: String
-) : ByteArrayProperty<String>(name) {
+) : ByteArrayPropertyWithLength<String>(name) {
   override fun getValue(thisRef: TypedByteArray, property: KProperty<*>): String {
     return thisRef.data.getClob(getIndex(thisRef))
   }
 
   override fun setValue(thisRef: TypedByteArray, property: KProperty<*>, value: String) {
-    thisRef.data.setClob(getIndex(thisRef), value)
+    thisRef.data.setClob(getIndex(thisRef), value, getMaxLength(thisRef))
   }
 }
 
 class BlobProperty(
   name: String
-) : ByteArrayProperty<SlicedByteArray>(name) {
+) : ByteArrayPropertyWithLength<SlicedByteArray>(name) {
+
   override fun getValue(thisRef: TypedByteArray, property: KProperty<*>): SlicedByteArray {
-    val result = thisRef.data.getBlob(getIndex(thisRef))
+    val result = thisRef.data.getBlob(getIndex(thisRef), getMaxLength(thisRef))
     return result
   }
 
   override fun setValue(thisRef: TypedByteArray, property: KProperty<*>, value: SlicedByteArray) {
-    thisRef.data.setBlob(getIndex(thisRef), value)
+    thisRef.data.setBlob(getIndex(thisRef), value, getMaxLength(thisRef))
   }
 }
 
diff --git a/src/commonMain/kotlin/nl/astraeus/tba/SlicedByteArray.kt b/src/commonMain/kotlin/nl/astraeus/tba/SlicedByteArray.kt
index f41d9c7..21fcf49 100644
--- a/src/commonMain/kotlin/nl/astraeus/tba/SlicedByteArray.kt
+++ b/src/commonMain/kotlin/nl/astraeus/tba/SlicedByteArray.kt
@@ -19,20 +19,20 @@ class SlicedByteArray(
   }
 
   fun setShort(index: Int, value: Short) {
-    check(offset + index + 1 < offset + length) { "Index out of bounds" }
+    check(offset + index + 1 <= offset + length) { "Index out of bounds" }
 
     data[offset + index] = (value.toInt() shr 8).toByte()
     data[offset + index + 1] = value.toByte()
   }
 
   fun getShort(index: Int): Short {
-    check(offset + index + 1 < offset + length) { "Index out of bounds, ${offset + index + 1} > ${offset + length} ($offset, $index, $length)" }
+    check(offset + index + 1 <= offset + length) { "Index out of bounds, ${offset + index + 1} > ${offset + length} ($offset, $index, $length)" }
 
     return ((data[offset + index].toInt() shl 8) or (data[offset + index + 1].toInt() and 0xff)).toShort()
   }
 
   fun setInt(index: Int, value: Int) {
-    check(offset + index + 3 < offset + length) { "Index out of bounds" }
+    check(offset + index + 3 <= offset + length) { "Index out of bounds" }
 
     data[offset + index] = ((value shr 24) and 0xff).toByte()
     data[offset + index + 1] = ((value shr 16) and 0xff).toByte()
@@ -41,7 +41,7 @@ class SlicedByteArray(
   }
 
   fun getInt(index: Int): Int {
-    check(offset + index + 3 < offset + length) { "Index out of bounds" }
+    check(offset + index + 3 <= offset + length) { "Index out of bounds" }
     return (
         (data[offset + index].toInt() shl 24) or
             ((data[offset + index+1].toInt() shl 16) and 0xff0000) or
@@ -51,7 +51,7 @@ class SlicedByteArray(
   }
 
   fun setLong(index: Int, value: Long) {
-    check(offset + index + 7 < offset + length) { "Index out of bounds" }
+    check(offset + index + 7 <= offset + length) { "Index out of bounds" }
     data[offset + index] = ((value shr 56) and 0xff).toByte()
     data[offset + index + 1] = ((value shr 48) and 0xff).toByte()
     data[offset + index + 2] = ((value shr 40) and 0xff).toByte()
@@ -63,7 +63,7 @@ class SlicedByteArray(
   }
 
   fun getLong(index: Int): Long {
-    check(offset + index + 7 < offset + length) { "Index out of bounds" }
+    check(offset + index + 7 <= offset + length) { "Index out of bounds" }
     return (
         (data[offset + index].toLong() shl 56) or
             ((data[offset + index+1].toLong() and 0xff) shl 48) or
@@ -107,15 +107,15 @@ class SlicedByteArray(
 
   fun toByteArray(): ByteArray = data.copyOfRange(offset, offset + length)
 
-  fun setBlob(index: Int, bytes: SlicedByteArray) {
-    if (index + bytes.size > length) {
+  fun setBlob(index: Int, bytes: SlicedByteArray, blobLength: Int) {
+    if (bytes.size > blobLength) {
       throw IllegalArgumentException("Blob is too long")
     }
     bytes.copyInto(data, offset + index, bytes.size)
     data.fill(
       0,
       offset + index + bytes.size,
-      offset + length
+      offset + index + blobLength
     )
   }
 
diff --git a/src/commonTest/kotlin/nl/astraeus/tba/ExtendedByteArrayDefinition.kt b/src/commonTest/kotlin/nl/astraeus/tba/ExtendedByteArrayDefinition.kt
index 80354c6..b2918b8 100644
--- a/src/commonTest/kotlin/nl/astraeus/tba/ExtendedByteArrayDefinition.kt
+++ b/src/commonTest/kotlin/nl/astraeus/tba/ExtendedByteArrayDefinition.kt
@@ -51,7 +51,7 @@ class ExtendedByteArrayDefinition {
 
   @Test
   fun testSimpleTypedByteArray() {
-    val exception = assertFailsWith(IllegalArgumentException::class) {
+    val exception = assertFailsWith(IllegalStateException::class) {
       PersonMessage(
         12,
         123,