diff --git a/libraries/tools/kotlin-gradle-plugin-integration-tests/src/test/kotlin/org/jetbrains/kotlin/gradle/Kapt3AndroidIT.kt b/libraries/tools/kotlin-gradle-plugin-integration-tests/src/test/kotlin/org/jetbrains/kotlin/gradle/Kapt3AndroidIT.kt
index a9533e17663..edf5717a41d 100644
--- a/libraries/tools/kotlin-gradle-plugin-integration-tests/src/test/kotlin/org/jetbrains/kotlin/gradle/Kapt3AndroidIT.kt
+++ b/libraries/tools/kotlin-gradle-plugin-integration-tests/src/test/kotlin/org/jetbrains/kotlin/gradle/Kapt3AndroidIT.kt
@@ -1,11 +1,10 @@
 package org.jetbrains.kotlin.gradle
 
-import org.jetbrains.kotlin.gradle.util.AGPVersion
-import org.jetbrains.kotlin.gradle.util.checkedReplace
-import org.jetbrains.kotlin.gradle.util.getFileByName
-import org.jetbrains.kotlin.gradle.util.modify
+import org.jetbrains.kotlin.gradle.util.*
 import org.jetbrains.kotlin.test.KotlinTestUtils
+import org.junit.Assert
 import org.junit.Test
+import java.io.File
 
 class Kapt3WorkersAndroid32IT : Kapt3Android32IT() {
     override fun kaptOptions(): KaptOptions =
@@ -36,6 +35,44 @@ open class Kapt3Android33IT : Kapt3AndroidIT() {
             assertFileExists("build/tmp/kotlin-classes/debug/test/androidx/navigation/StartFragmentKt.class")
         }
     }
+
+    /** Regression test for Android projects and KT-31127. */
+    @Test
+    fun testKotlinProcessorUsingFiler() {
+        val project = Project("AndroidLibraryKotlinProject").apply {
+            setupWorkingDir()
+            gradleBuildScript().appendText(
+                """
+                apply plugin: 'kotlin-kapt'
+                android {
+                    defaultConfig.javaCompileOptions.annotationProcessorOptions.includeCompileClasspath = false
+
+                    libraryVariants.all {
+                        it.generateBuildConfig.enabled = false
+                    }
+                }
+
+                dependencies {
+                    kapt "org.jetbrains.kotlin:annotation-processor-example:${"$"}kotlin_version"
+                    implementation "org.jetbrains.kotlin:annotation-processor-example:${"$"}kotlin_version"
+                }
+            """.trimIndent()
+            )
+
+            // The test must not contain any java sources in order to detect the issue.
+            Assert.assertEquals(emptyList<File>(), projectDir.allJavaFiles().toList())
+            projectDir.getFileByName("Dummy.kt").modify {
+                it.replace("class Dummy", "@example.KotlinFilerGenerated class Dummy")
+            }
+        }
+
+        project.build("assembleDebug") {
+            assertSuccessful()
+            assertFileExists("build/generated/source/kapt/debug/demo/DummyGenerated.kt")
+            assertTasksExecuted(":compileDebugKotlin")
+            assertTasksSkipped(":compileDebugJavaWithJavac")
+        }
+    }
 }
 
 class Kapt3Android31IT : Kapt3AndroidIT() {
diff --git a/libraries/tools/kotlin-gradle-plugin-integration-tests/src/test/resources/testProject/AndroidLibraryKotlinProject/build.gradle b/libraries/tools/kotlin-gradle-plugin-integration-tests/src/test/resources/testProject/AndroidLibraryKotlinProject/build.gradle
new file mode 100644
index 00000000000..463e39d4b86
--- /dev/null
+++ b/libraries/tools/kotlin-gradle-plugin-integration-tests/src/test/resources/testProject/AndroidLibraryKotlinProject/build.gradle
@@ -0,0 +1,29 @@
+buildscript {
+    repositories {
+        mavenLocal()
+        maven { url 'https://maven.google.com' }
+        jcenter()
+    }
+    dependencies {
+        classpath "org.jetbrains.kotlin:kotlin-gradle-plugin:$kotlin_version"
+        classpath('com.android.tools.build:gradle:' + android_tools_version)
+    }
+}
+
+repositories {
+    mavenLocal()
+    maven { url 'https://maven.google.com' }
+    jcenter()
+}
+
+apply plugin: 'com.android.library'
+apply plugin: 'kotlin-android'
+
+android {
+    compileSdkVersion 23
+    buildToolsVersion "25.0.2"
+}
+
+dependencies {
+    compile "org.jetbrains.kotlin:kotlin-stdlib:$kotlin_version"
+}
diff --git a/libraries/tools/kotlin-gradle-plugin-integration-tests/src/test/resources/testProject/AndroidLibraryKotlinProject/gradle.properties b/libraries/tools/kotlin-gradle-plugin-integration-tests/src/test/resources/testProject/AndroidLibraryKotlinProject/gradle.properties
new file mode 100644
index 00000000000..59b261a6689
--- /dev/null
+++ b/libraries/tools/kotlin-gradle-plugin-integration-tests/src/test/resources/testProject/AndroidLibraryKotlinProject/gradle.properties
@@ -0,0 +1 @@
+org.gradle.jvmargs=-XX:MaxPermSize=512m
\ No newline at end of file
diff --git a/libraries/tools/kotlin-gradle-plugin-integration-tests/src/test/resources/testProject/AndroidLibraryKotlinProject/src/main/AndroidManifest.xml b/libraries/tools/kotlin-gradle-plugin-integration-tests/src/test/resources/testProject/AndroidLibraryKotlinProject/src/main/AndroidManifest.xml
new file mode 100644
index 00000000000..d5d65ecfca9
--- /dev/null
+++ b/libraries/tools/kotlin-gradle-plugin-integration-tests/src/test/resources/testProject/AndroidLibraryKotlinProject/src/main/AndroidManifest.xml
@@ -0,0 +1,9 @@
+<?xml version="1.0" encoding="utf-8"?>
+<manifest xmlns:android="http://schemas.android.com/apk/res/android"
+          package="org.jetbrains.kotlin.gradle.test.android.libalfa"
+          android:versionCode="1"
+          android:versionName="1.0" >
+
+  <application/>
+
+</manifest>
diff --git a/libraries/tools/kotlin-gradle-plugin-integration-tests/src/test/resources/testProject/AndroidLibraryKotlinProject/src/main/kotlin/Dummy.kt b/libraries/tools/kotlin-gradle-plugin-integration-tests/src/test/resources/testProject/AndroidLibraryKotlinProject/src/main/kotlin/Dummy.kt
new file mode 100644
index 00000000000..9c033c2608b
--- /dev/null
+++ b/libraries/tools/kotlin-gradle-plugin-integration-tests/src/test/resources/testProject/AndroidLibraryKotlinProject/src/main/kotlin/Dummy.kt
@@ -0,0 +1,3 @@
+package demo
+
+class Dummy
diff --git a/libraries/tools/kotlin-gradle-plugin-integration-tests/src/test/resources/testProject/AndroidLibraryKotlinProject/src/main/kotlin/Greeter.kt b/libraries/tools/kotlin-gradle-plugin-integration-tests/src/test/resources/testProject/AndroidLibraryKotlinProject/src/main/kotlin/Greeter.kt
new file mode 100644
index 00000000000..accb6e430f8
--- /dev/null
+++ b/libraries/tools/kotlin-gradle-plugin-integration-tests/src/test/resources/testProject/AndroidLibraryKotlinProject/src/main/kotlin/Greeter.kt
@@ -0,0 +1,3 @@
+package demo
+
+open class Greeter(val greeting: String)
diff --git a/libraries/tools/kotlin-gradle-plugin-integration-tests/src/test/resources/testProject/AndroidLibraryKotlinProject/src/main/kotlin/dummyUtil.kt b/libraries/tools/kotlin-gradle-plugin-integration-tests/src/test/resources/testProject/AndroidLibraryKotlinProject/src/main/kotlin/dummyUtil.kt
new file mode 100644
index 00000000000..2bf9f3e293a
--- /dev/null
+++ b/libraries/tools/kotlin-gradle-plugin-integration-tests/src/test/resources/testProject/AndroidLibraryKotlinProject/src/main/kotlin/dummyUtil.kt
@@ -0,0 +1,3 @@
+package demo
+
+fun dummyFun() {}
\ No newline at end of file
diff --git a/libraries/tools/kotlin-gradle-plugin/src/main/kotlin/org/jetbrains/kotlin/gradle/targets/android/Android25ProjectHandler.kt b/libraries/tools/kotlin-gradle-plugin/src/main/kotlin/org/jetbrains/kotlin/gradle/targets/android/Android25ProjectHandler.kt
index 36bdcf3fbdd..98af1ca1e4f 100644
--- a/libraries/tools/kotlin-gradle-plugin/src/main/kotlin/org/jetbrains/kotlin/gradle/targets/android/Android25ProjectHandler.kt
+++ b/libraries/tools/kotlin-gradle-plugin/src/main/kotlin/org/jetbrains/kotlin/gradle/targets/android/Android25ProjectHandler.kt
@@ -191,6 +191,7 @@ class Android25ProjectHandler(
             javaTask: AbstractCompile
         ) {
             val kaptSourceOutput = project.fileTree(kaptTask.destinationDir).builtBy(kaptTask)
+            kaptSourceOutput.include("**/*.java")
             variantData.registerExternalAptJavaOutput(kaptSourceOutput)
             variantData.dataBindingDependencyArtifactsIfSupported?.let { kaptTask.dependsOn(it) }
         }