diff --git a/README.md b/README.md
index f493ea0..be7163a 100644
--- a/README.md
+++ b/README.md
@@ -22,6 +22,7 @@ The **Kotlin Object Multiplatform Mapper** provides you a possibility to generat
   * [Configuration](#mapping-configuration)
     * [Disable AutoCast](#disable-autocast)
     * [Change Convert Function Name](#change-convert-function-name)
+  * [@MapFunction](#mapfunction-annotation)
   * [@MapName](#mapname-annotation)
   * [@MapEmbedded](#mapembedded-annotation)
   * [@MapConverter](#use-converter)
@@ -55,6 +56,7 @@ The **Kotlin Object Multiplatform Mapper** provides you a possibility to generat
 * Has next properties annotations:
   * Specify mapping from property with different name
   * Specify a converter to map data from source unusual way
+  * Specify a top-level extension function for property casting
   * Specify a resolver to map default values into properties
   * Specify null substitute to map nullable properties into not-nullable
 * Support extension via plugins
@@ -84,7 +86,7 @@ plugins {
     id("com.google.devtools.ksp") version "2.3.9"
 }
 
-val kommVersion = "0.60.0"
+val kommVersion = "0.61.6"
 
 depensencies {
     implementation("com.ucasoft.komm:komm-annotations:$kommVersion")
@@ -97,7 +99,7 @@ plugins {
     id("com.google.devtools.ksp") version "2.3.9"
 }
 
-val kommVersion = "0.60.0"
+val kommVersion = "0.61.6"
 
 kotlin {
     jvm {
@@ -222,6 +224,42 @@ fun SourceObject.convertToDestination(): DestinationObject = DestinationObject(
 }
 ```
 
+### @MapFunction annotation
+Use `@MapFunction` when the automatic `toType()` cast should call a top-level extension function from another package.
+KOMM imports the function and keeps extension-call syntax in generated code.
+
+#### Function declaration
+```kotlin
+fun ByteArray.toImageBitmap(): ImageBitmap = //...
+```
+#### Classes declaration
+```kotlin
+data class SourceObject(
+    val logo: ByteArray?
+)
+
+@KOMMMap(from = [SourceObject::class])
+data class DestinationObject(
+    @MapFunction(packageName = "com.test.converters")
+    val logo: ImageBitmap?
+)
+```
+or specify the function name explicitly:
+```kotlin
+@MapFunction(
+    packageName = "com.test.converters",
+    name = "toImageBitmap"
+)
+```
+#### Generated extension function
+```kotlin
+import com.test.converters.toImageBitmap
+
+fun SourceObject.toDestinationObject(): DestinationObject = DestinationObject(
+    logo = logo?.toImageBitmap()
+)
+```
+
 ### @MapName annotation
 #### Classes declaration
 ```kotlin
@@ -528,7 +566,7 @@ plugins {
     id("com.google.devtools.ksp") version "2.3.9"
 }
 
-val kommVersion = "0.60.0"
+val kommVersion = "0.61.6"
 
 depensencies {
     implementation("com.ucasoft.komm:komm-annotations:$kommVersion")
@@ -542,7 +580,7 @@ plugins {
     id("com.google.devtools.ksp") version "2.3.9"
 }
 
-val kommVersion = "0.60.0"
+val kommVersion = "0.61.6"
 
 //...
 
@@ -602,7 +640,7 @@ plugins {
     id("com.google.devtools.ksp") version "2.3.9"
 }
 
-val kommVersion = "0.60.0"
+val kommVersion = "0.61.6"
 
 depensencies {
     implementation("com.ucasoft.komm:komm-annotations:$kommVersion")
@@ -646,7 +684,7 @@ plugins {
     id("com.google.devtools.ksp") version "2.3.9"
 }
 
-val kommVersion = "0.60.0"
+val kommVersion = "0.61.6"
 
 depensencies {
     implementation("com.ucasoft.komm:komm-annotations:$kommVersion")
@@ -660,7 +698,7 @@ plugins {
     id("com.google.devtools.ksp") version "2.3.9"
 }
 
-val kommVersion = "0.60.0"
+val kommVersion = "0.61.6"
 
 //...
 
diff --git a/build.gradle.kts b/build.gradle.kts
index 8c0f5ae..ea952c0 100644
--- a/build.gradle.kts
+++ b/build.gradle.kts
@@ -12,7 +12,7 @@ tasks.wrapper {
 allprojects {
     group = "com.ucasoft.komm"
 
-    version = "0.60.0"
+    version = "0.61.6"
 
     repositories {
         mavenCentral()
diff --git a/komm-annotations/src/main/kotlin/com/ucasoft/komm/annotations/MapFunction.kt b/komm-annotations/src/main/kotlin/com/ucasoft/komm/annotations/MapFunction.kt
new file mode 100644
index 0000000..0b99980
--- /dev/null
+++ b/komm-annotations/src/main/kotlin/com/ucasoft/komm/annotations/MapFunction.kt
@@ -0,0 +1,12 @@
+package com.ucasoft.komm.annotations
+
+import kotlin.reflect.KClass
+
+@Target(AnnotationTarget.PROPERTY)
+@Retention(AnnotationRetention.SOURCE)
+@Repeatable
+annotation class MapFunction(
+    val packageName: String,
+    val name: String = "",
+    val `for`: Array<KClass<*>> = []
+)
diff --git a/komm-processor/src/main/kotlin/com/ucasoft/komm/processor/KOMMAnnotationFinder.kt b/komm-processor/src/main/kotlin/com/ucasoft/komm/processor/KOMMAnnotationFinder.kt
index d3443ef..e07532a 100644
--- a/komm-processor/src/main/kotlin/com/ucasoft/komm/processor/KOMMAnnotationFinder.kt
+++ b/komm-processor/src/main/kotlin/com/ucasoft/komm/processor/KOMMAnnotationFinder.kt
@@ -36,6 +36,25 @@ class KOMMAnnotationFinder(private val forClass: KSType) {
             MapConvert<*, *, *>::converter.name
         )
 
+    fun findFunction(member: KSPropertyDeclaration): Pair<String, String>? {
+        val annotations = member.annotations.filter { it.shortName.asString() == MapFunction::class.simpleName }
+            .associateWith(::associateWithFor)
+
+        val annotation = filterAnnotationsByClass(forClass.toClassName(), annotations, member)
+            ?: return null
+
+        val packageName = annotation.arguments
+            .first { it.name?.asString() == MapFunction::packageName.name }
+            .value
+            .toString()
+        val name = annotation.arguments
+            .first { it.name?.asString() == MapFunction::name.name }
+            .value
+            .toString()
+
+        return packageName to name
+    }
+
     fun findSubstituteResolver(member: KSPropertyDeclaration): String? {
         val annotations = member.annotations.filter { it.shortName.asString() == NullSubstitute::class.simpleName }
             .associateWith(::associateWithFor)
diff --git a/komm-processor/src/main/kotlin/com/ucasoft/komm/processor/KOMMPropertyMapper.kt b/komm-processor/src/main/kotlin/com/ucasoft/komm/processor/KOMMPropertyMapper.kt
index 33cca73..fcbe624 100644
--- a/komm-processor/src/main/kotlin/com/ucasoft/komm/processor/KOMMPropertyMapper.kt
+++ b/komm-processor/src/main/kotlin/com/ucasoft/komm/processor/KOMMPropertyMapper.kt
@@ -14,7 +14,8 @@ class KOMMPropertyMapper(
     destination: KSType,
     private val direction: KOMMVisitor.Direction,
     private val config: KSAnnotation,
-    private val plugins: List<KOMMCastPlugin>
+    private val plugins: List<KOMMCastPlugin>,
+    private val imports: MutableMap<String, List<String>>
 ) {
 
     private val annotationFinder = KOMMAnnotationFinder(
@@ -44,6 +45,12 @@ class KOMMPropertyMapper(
                 annotationFinder.findConverter(it)
             }
         }
+        val function = when (direction) {
+            KOMMVisitor.Direction.From -> annotationFinder.findFunction(destination)
+            KOMMVisitor.Direction.To -> (sourceProperty as? KSPropertyDeclaration)?.let {
+                annotationFinder.findFunction(it)
+            }
+        }
         val nullSubstituteResolver = when (direction) {
             KOMMVisitor.Direction.From -> annotationFinder.findSubstituteResolver(destination)
             KOMMVisitor.Direction.To -> (sourceProperty as? KSPropertyDeclaration)?.let {
@@ -54,10 +61,10 @@ class KOMMPropertyMapper(
             "$destination = $converter(this).convert(${getSourceAccessName(source)})"
         } else if (nullSubstituteResolver != null) {
             "$destination = ${
-                getSourceWithCast(destination, source, config, useSafeAccess = true)
+                getSourceWithCast(destination, source, config, function, useSafeAccess = true)
             } ?: ${mapResolver(nullSubstituteResolver, mapTo)}"
         } else {
-            "$destination = ${getSourceWithCast(destination, source, config)}"
+            "$destination = ${getSourceWithCast(destination, source, config, function)}"
         }
     }
 
@@ -175,6 +182,7 @@ class KOMMPropertyMapper(
         destinationProperty: KSPropertyDeclaration,
         source: EmbeddedSourceProperty,
         config: KSAnnotation,
+        function: Pair<String, String>?,
         useSafeAccess: Boolean = false
     ): String {
         val propertyName = getSourceAccessName(source, useSafeAccess)
@@ -215,12 +223,21 @@ class KOMMPropertyMapper(
             return if (useSafeAccess) propertyName else getSourceAccessName(source, assertNotNull = true)
         }
 
-        return "${
-            if (sourceIsNullable && !useSafeAccess) getSourceAccessName(
-                source,
-                assertNotNull = true
-            ) else propertyName
-        }${if (sourceIsNullable && useSafeAccess) "?" else ""}.to${destinationProperty.type}()"
+        val shouldUseSafeCall = sourceIsNullable && (useSafeAccess || destinationIsNullable)
+        val sourceAccessName = when {
+            shouldUseSafeCall -> getSourceAccessName(source, useSafeAccess = true)
+            sourceIsNullable -> getSourceAccessName(source, assertNotNull = true)
+            else -> propertyName
+        }
+
+        val conversionFunctionName = "to${destinationType.declaration.simpleName.asString()}"
+        val functionName = function?.second?.ifEmpty { conversionFunctionName } ?: conversionFunctionName
+        if (function != null) {
+            imports[function.first] = imports[function.first].orEmpty() + functionName
+        }
+        val receiverPrefix = "$sourceAccessName${if (shouldUseSafeCall) "?." else "."}"
+
+        return "$receiverPrefix$functionName()"
     }
 
     private fun getSourceWithPluginCast(
diff --git a/komm-processor/src/main/kotlin/com/ucasoft/komm/processor/KOMMSymbolProcessor.kt b/komm-processor/src/main/kotlin/com/ucasoft/komm/processor/KOMMSymbolProcessor.kt
index 30004f0..c06b114 100644
--- a/komm-processor/src/main/kotlin/com/ucasoft/komm/processor/KOMMSymbolProcessor.kt
+++ b/komm-processor/src/main/kotlin/com/ucasoft/komm/processor/KOMMSymbolProcessor.kt
@@ -23,8 +23,9 @@ class KOMMSymbolProcessor(
 
         val symbols =
             resolver.getSymbolsWithAnnotation(KOMMMap::class.qualifiedName!!).filterIsInstance<KSClassDeclaration>()
+                .toList()
 
-        if (!symbols.iterator().hasNext()) {
+        if (symbols.isEmpty()) {
             return emptyList()
         }
 
@@ -41,15 +42,15 @@ class KOMMSymbolProcessor(
             val file = FileSpec
                 .builder(packageName.asString(), "MappingExtensions")
                 .apply {
-                    imports.forEach { this.addImport(it.key, it.value) }
+                    imports.forEach { addImport(it.key, it.value) }
                     functions.forEach { this.addFunction(it) }
                 }
                 .build()
 
-            file.writeTo(codeGenerator, false)
+            file.writeTo(codeGenerator, true, classDeclarations.mapNotNull { it.containingFile })
         }
 
-        return symbols.filterNot { it.validate() }.toList()
+        return symbols.filterNot { it.validate() }
     }
 
     private fun loadPlugins(): Map<KClass<out KOMMPlugin>, List<Class<*>>> {
@@ -66,4 +67,4 @@ class KOMMSymbolProcessor(
                 }.mapValues { it.value.map { it.second } }
         }
     }
-}
\ No newline at end of file
+}
diff --git a/komm-processor/src/main/kotlin/com/ucasoft/komm/processor/KOMMVisitor.kt b/komm-processor/src/main/kotlin/com/ucasoft/komm/processor/KOMMVisitor.kt
index a3ffe79..a3806df 100755
--- a/komm-processor/src/main/kotlin/com/ucasoft/komm/processor/KOMMVisitor.kt
+++ b/komm-processor/src/main/kotlin/com/ucasoft/komm/processor/KOMMVisitor.kt
@@ -2,6 +2,7 @@ package com.ucasoft.komm.processor
 
 import com.google.devtools.ksp.isPrivate
 import com.google.devtools.ksp.symbol.*
+import com.squareup.kotlinpoet.CodeBlock
 import com.squareup.kotlinpoet.FunSpec
 import com.squareup.kotlinpoet.TypeName
 import com.squareup.kotlinpoet.asTypeName
@@ -64,10 +65,13 @@ class KOMMVisitor(
     }
 
     private fun syncImports(destination: KSType, source: KSType, imports: MutableMap<String, List<String>>) {
-        val destinationPackageName = destination.toClassName().packageName
-        val sourcePackageName = source.toClassName().packageName
-        if (sourcePackageName != destinationPackageName) {
-            imports[sourcePackageName] = imports[sourcePackageName].orEmpty() + source.toClassName().simpleName
+        val destinationClassName = destination.toClassName()
+        val sourceClassName = source.toClassName()
+        if (
+            sourceClassName.packageName != destinationClassName.packageName &&
+            sourceClassName.simpleName != destinationClassName.simpleName
+        ) {
+            imports[sourceClassName.packageName] = imports[sourceClassName.packageName].orEmpty() + sourceClassName.simpleName
         }
     }
 
@@ -77,7 +81,7 @@ class KOMMVisitor(
         return FunSpec.builder(fromSourceFunctionName)
             .receiver(getSourceName(source))
             .returns(destination.toClassName())
-            .addStatement(buildStatement(source, destination.declaration as KSClassDeclaration, direction, config))
+            .addCode(buildStatement(source, destination.declaration as KSClassDeclaration, direction, config))
             .build()
     }
 
@@ -95,13 +99,13 @@ class KOMMVisitor(
         return source.toTypeName()
     }
 
-    private fun buildStatement(source: KSType, destination: KSClassDeclaration, direction: Direction, config: KSAnnotation): String {
+    private fun buildStatement(source: KSType, destination: KSClassDeclaration, direction: Direction, config: KSAnnotation): CodeBlock {
         val castPlugins = typePlugins.toMutableList().apply {
                 addAll(plugins[KOMMCastPlugin::class]
                     ?.map { it.getDeclaredConstructor().newInstance() } ?: emptyList())
             }.filterIsInstance<KOMMCastPlugin>()
 
-        val propertyMapper = KOMMPropertyMapper(source, destination.asStarProjectedType(), direction, config, castPlugins)
+        val propertyMapper = KOMMPropertyMapper(source, destination.asStarProjectedType(), direction, config, castPlugins, imports)
         val properties = destination.getAllProperties().groupBy { p ->
             destination.primaryConstructor?.parameters?.any { it.name == p.simpleName }
         }
@@ -116,8 +120,8 @@ class KOMMVisitor(
             propertyMapper.map(it, MapTo.Also)
         }
 
-        return buildString {
-            appendLine("return $destination(")
+        val statement = buildString {
+            appendLine("return %T(")
             constructorProperties?.forEach { appendLine("\t$it,") }
             deleteLast(2)
             if (noConstructorProperties.isNullOrEmpty()) {
@@ -128,9 +132,11 @@ class KOMMVisitor(
                 append("}")
             }
         }
+
+        return CodeBlock.of(statement, destination.toClassName())
     }
 
     private fun StringBuilder.deleteLast(length: Int) = this.delete(this.length - length, this.length - 1)!!
 
     private fun KSType.isKotlinClass() = declaration.origin == Origin.KOTLIN
-}
\ No newline at end of file
+}
diff --git a/komm-processor/src/test/kotlin/com/ucasoft/komm/processor/CastTests.kt b/komm-processor/src/test/kotlin/com/ucasoft/komm/processor/CastTests.kt
index d9827ee..1515ea7 100755
--- a/komm-processor/src/test/kotlin/com/ucasoft/komm/processor/CastTests.kt
+++ b/komm-processor/src/test/kotlin/com/ucasoft/komm/processor/CastTests.kt
@@ -1,12 +1,17 @@
 package com.ucasoft.komm.processor
 
+import com.squareup.kotlinpoet.ClassName
+import com.squareup.kotlinpoet.FileSpec
+import com.squareup.kotlinpoet.FunSpec
 import com.squareup.kotlinpoet.INT
 import com.squareup.kotlinpoet.STRING
+import com.squareup.kotlinpoet.TypeSpec
 import com.squareup.kotlinpoet.asClassName
 import com.tschuchort.compiletesting.KotlinCompilation
 import com.ucasoft.komm.annotations.KOMMMap
 import com.ucasoft.komm.annotations.MapConfiguration
 import com.ucasoft.komm.annotations.MapConvert
+import com.ucasoft.komm.annotations.MapFunction
 import com.ucasoft.komm.processor.exceptions.KOMMCastException
 import io.kotest.assertions.throwables.shouldThrow
 import io.kotest.matchers.nulls.shouldNotBeNull
@@ -128,6 +133,66 @@ internal class CastTests: CompilationTests() {
         }
     }
 
+    @Test
+    fun nullableSourceCastsToNullableDestinationWithSafeCall() {
+        val sourceObjectClassName = ClassName(packageName, "SourceObject")
+        val imageBitmapClassName = ClassName(packageName, "ImageBitmap")
+        val byteArrayClassName = ClassName("kotlin", "ByteArray")
+        val convertersPackageName = "$packageName.converters"
+        val propertyName = "logo"
+        val generated = generate(
+            FileSpec.builder(packageName, "ImageBitmap.kt")
+                .addType(TypeSpec.classBuilder(imageBitmapClassName).build())
+                .build(),
+            FileSpec.builder(convertersPackageName, "ImageBitmapConverters.kt")
+                .addFunction(
+                    FunSpec.builder("toImageBitmap")
+                        .receiver(byteArrayClassName)
+                        .returns(imageBitmapClassName)
+                        .addStatement("return %T()", imageBitmapClassName)
+                        .build()
+                )
+                .build(),
+            buildFileSpec(
+                sourceObjectClassName.simpleName,
+                mapOf(propertyName to PropertySpecInit(byteArrayClassName, isNullable = true))
+            ),
+            buildFileSpec(
+                "DestinationObject",
+                mapOf(
+                    propertyName to PropertySpecInit(
+                        imageBitmapClassName,
+                        isNullable = true,
+                        annotations = listOf(
+                            MapFunction::class to mapOf(
+                                "packageName = %S" to listOf(convertersPackageName)
+                            )
+                        )
+                    )
+                ),
+                listOf(KOMMMap::class to mapOf("from = %L" to listOf("[${sourceObjectClassName.simpleName}::class]")))
+            )
+        )
+
+        generated.exitCode.shouldBe(KotlinCompilation.ExitCode.OK)
+
+        val mappingClass = generated.classLoader.loadClass("$packageName.MappingExtensionsKt")
+        val mappingMethod = mappingClass.declaredMethods.first()
+        val sourceClass = generated.classLoader.loadClass(sourceObjectClassName.canonicalName)
+
+        val nullSourceInstance = sourceClass.constructors.first().newInstance(null)
+        val nullDestinationInstance = mappingMethod.invoke(null, nullSourceInstance)
+        nullDestinationInstance::class.shouldHaveMemberProperty(propertyName) {
+            it.getter.call(nullDestinationInstance).shouldBe(null)
+        }
+
+        val sourceInstance = sourceClass.constructors.first().newInstance(byteArrayOf(1))
+        val destinationInstance = mappingMethod.invoke(null, sourceInstance)
+        destinationInstance::class.shouldHaveMemberProperty(propertyName) {
+            it.getter.call(destinationInstance).shouldNotBeNull()
+        }
+    }
+
     companion object {
 
         @JvmStatic
@@ -146,4 +211,4 @@ internal class CastTests: CompilationTests() {
             )
         )
     }
-}
\ No newline at end of file
+}
diff --git a/komm-processor/src/test/kotlin/com/ucasoft/komm/processor/CompilationTests.kt b/komm-processor/src/test/kotlin/com/ucasoft/komm/processor/CompilationTests.kt
index eb06fad..b30b4df 100644
--- a/komm-processor/src/test/kotlin/com/ucasoft/komm/processor/CompilationTests.kt
+++ b/komm-processor/src/test/kotlin/com/ucasoft/komm/processor/CompilationTests.kt
@@ -21,9 +21,10 @@ abstract class CompilationTests {
         className: String,
         constructorProperties: Map<String, PropertySpecInit>,
         classAnnotations: List<Pair<KClass<out Annotation>, Map<String, List<Any>>>> = emptyList(),
-        properties: Map<String, PropertySpecInit> = emptyMap()
+        properties: Map<String, PropertySpecInit> = emptyMap(),
+        `package`: String = packageName
     ) = FileSpec
-        .builder(packageName, "$className.kt")
+        .builder(`package`, "$className.kt")
         .addImport("com.ucasoft.komm.annotations", "MapConfiguration", "MapDefault")
         .addImport("java.util", "Currency")
         .addType(
@@ -100,7 +101,7 @@ abstract class CompilationTests {
 
     fun generate(vararg fileSpec: FileSpec) = KotlinCompilation().apply {
         inheritClassPath = true
-        sources = fileSpec.map { SourceFile.kotlin(it.name, it.toString()) }
+        sources = fileSpec.map { SourceFile.kotlin("${it.packageName.replace('.', '/')}/${it.name}", it.toString()) }
         workingDir = tempDir
         configureKsp {
             symbolProcessorProviders.add(KOMMProcessorProvider())
@@ -139,4 +140,4 @@ abstract class CompilationTests {
         val parametrizedAnnotations: List<Pair<ParameterizedTypeName, Map<String, List<Any>>>> = emptyList(),
         val parametrizedType: KClass<*>? = null
     )
-}
\ No newline at end of file
+}
diff --git a/komm-processor/src/test/kotlin/com/ucasoft/komm/processor/ProcessorTests.kt b/komm-processor/src/test/kotlin/com/ucasoft/komm/processor/ProcessorTests.kt
index 4a307b7..a3e4754 100755
--- a/komm-processor/src/test/kotlin/com/ucasoft/komm/processor/ProcessorTests.kt
+++ b/komm-processor/src/test/kotlin/com/ucasoft/komm/processor/ProcessorTests.kt
@@ -187,6 +187,34 @@ internal class ProcessorTests : CompilationTests() {
         }
     }
 
+    @Test
+    fun mapsClassesWithSameSimpleNameFromDifferentPackages() {
+        val sourcePackageName = "$packageName.db"
+        val sourceSpec = buildFileSpec("Account", mapOf("id" to PropertySpecInit(INT)), `package` = sourcePackageName)
+        val generated = generate(
+            sourceSpec,
+            buildFileSpec(
+                "Account",
+                mapOf("id" to PropertySpecInit(INT)),
+                listOf(KOMMMap::class to mapOf("from = %L" to listOf("[$sourcePackageName.Account::class]")))
+            )
+        )
+
+        generated.exitCode.shouldBe(KotlinCompilation.ExitCode.OK)
+
+        val mappingClass = generated.classLoader.loadClass("$packageName.MappingExtensionsKt")
+        val mappingMethod = mappingClass.declaredMethods.first { it.name == "toAccount" }
+        val sourceClass = generated.classLoader.loadClass("$sourcePackageName.Account")
+        val destinationClass = generated.classLoader.loadClass("$packageName.Account")
+        val sourceInstance = sourceClass.constructors.first().newInstance(123)
+        val destinationInstance = mappingMethod.invoke(null, sourceInstance)
+
+        destinationInstance::class.java.shouldBe(destinationClass)
+        destinationInstance::class.shouldHaveMemberProperty("id") {
+            it.getter.call(destinationInstance).shouldBe(123)
+        }
+    }
+
     @Test
     fun toDestinationIsNotKotlinFails() {
         val generated = generate(
@@ -221,4 +249,4 @@ internal class ProcessorTests : CompilationTests() {
             )
         )
     }
-}
\ No newline at end of file
+}