diff --git a/plugins/kapt3/kapt3-compiler/src/org/jetbrains/kotlin/kapt3/Kapt3Extension.kt b/plugins/kapt3/kapt3-compiler/src/org/jetbrains/kotlin/kapt3/Kapt3Extension.kt
index 69d5c119ba3..e107cc3679c 100644
--- a/plugins/kapt3/kapt3-compiler/src/org/jetbrains/kotlin/kapt3/Kapt3Extension.kt
+++ b/plugins/kapt3/kapt3-compiler/src/org/jetbrains/kotlin/kapt3/Kapt3Extension.kt
@@ -102,7 +102,7 @@ class ClasspathBasedKapt3Extension(
     override fun loadProcessors(): List<Processor> {
         ClassUtilCore.clearJarURLCache()
 
-        val classpath = annotationProcessingClasspath + compileClasspath
+        val classpath = (annotationProcessingClasspath + compileClasspath).distinct()
         val classLoader = URLClassLoader(classpath.map { it.toURI().toURL() }.toTypedArray())
         this.annotationProcessingClassLoader = classLoader