diff --git a/ant/src/org/jetbrains/kotlin/ant/KotlinCompilerAdapter.java b/ant/src/org/jetbrains/kotlin/ant/KotlinCompilerAdapter.java
index 5017309c7b5..e3b941b1cc6 100644
--- a/ant/src/org/jetbrains/kotlin/ant/KotlinCompilerAdapter.java
+++ b/ant/src/org/jetbrains/kotlin/ant/KotlinCompilerAdapter.java
@@ -16,13 +16,21 @@
 
 package org.jetbrains.kotlin.ant;
 
+import kotlin.KotlinPackage;
+import kotlin.jvm.functions.Function1;
 import org.apache.tools.ant.BuildException;
 import org.apache.tools.ant.taskdefs.Javac;
-import org.apache.tools.ant.taskdefs.compilers.DefaultCompilerAdapter;
 import org.apache.tools.ant.taskdefs.compilers.Javac13;
 import org.apache.tools.ant.types.Path;
+import org.jetbrains.annotations.NotNull;
+
+import java.io.File;
+import java.util.Arrays;
+import java.util.List;
+
+public class KotlinCompilerAdapter extends Javac13 {
+    private static final List<String> KOTLIN_EXTENSIONS = Arrays.asList("kt", "kts");
 
-public class KotlinCompilerAdapter extends DefaultCompilerAdapter {
     private Path externalAnnotations;
 
     public void setExternalAnnotations(Path externalAnnotations) {
@@ -36,27 +44,53 @@ public class KotlinCompilerAdapter extends DefaultCompilerAdapter {
         return externalAnnotations.createPath();
     }
 
+    @Override
+    public String[] getSupportedFileExtensions() {
+        List<String> result = KotlinPackage.plus(Arrays.asList(super.getSupportedFileExtensions()), KOTLIN_EXTENSIONS);
+        //noinspection SSBasedInspection
+        return result.toArray(new String[result.size()]);
+    }
+
     @Override
     public boolean execute() throws BuildException {
         Javac javac = getJavac();
 
-        Kotlin2JvmTask kotlinTask = new Kotlin2JvmTask();
-        kotlinTask.setOutput(javac.getDestdir());
+        Kotlin2JvmTask kotlinc = new Kotlin2JvmTask();
+        kotlinc.setOutput(javac.getDestdir());
 
         Path classpath = javac.getClasspath();
         if (classpath != null) {
-            kotlinTask.setClasspath(classpath);
+            kotlinc.setClasspath(classpath);
         }
 
-        kotlinTask.setSrc(javac.getSrcdir());
-        kotlinTask.setExternalAnnotations(externalAnnotations);
+        // We use the provided src dir instead of compileList, because the latter is insane:
+        // it is constructed only of sources which are newer than classes with the same name
+        kotlinc.setSrc(javac.getSrcdir());
 
-        kotlinTask.execute();
+        kotlinc.setExternalAnnotations(externalAnnotations);
+
+        kotlinc.execute();
 
         javac.log("Running javac...");
 
-        Javac13 javac13 = new Javac13();
-        javac13.setJavac(javac);
-        return javac13.execute();
+        // Javac13#execute passes everything in compileList to javac, which doesn't recognize .kt files
+        compileList = filterOutKotlinSources(compileList);
+
+        return compileList.length == 0 || super.execute();
+    }
+
+    @NotNull
+    private static File[] filterOutKotlinSources(@NotNull File[] files) {
+        List<File> nonKotlinSources = KotlinPackage.filterNot(files, new Function1<File, Boolean>() {
+            @Override
+            public Boolean invoke(File file) {
+                for (String extension : KOTLIN_EXTENSIONS) {
+                    if (file.getPath().endsWith("." + extension)) return true;
+                }
+                return false;
+            }
+        });
+
+        return nonKotlinSources.toArray(new File[nonKotlinSources.size()]);
     }
 }
diff --git a/compiler/testData/integration/ant/jvm/externalAnnotations/build.log.expected b/compiler/testData/integration/ant/jvm/externalAnnotations/build.log.expected
index 1ee5576831e..b0482150f40 100644
--- a/compiler/testData/integration/ant/jvm/externalAnnotations/build.log.expected
+++ b/compiler/testData/integration/ant/jvm/externalAnnotations/build.log.expected
@@ -3,7 +3,7 @@ Buildfile: [TestData]/build.xml
 
 build:
     [mkdir] Created dir: [Temp]/classes
-    [javac] Compiling 1 source file to [Temp]/classes
+    [javac] Compiling 2 source files to [Temp]/classes
     [javac] Compiling [[TestData]/root1] => [[Temp]/classes]
     [javac] Running javac...
       [jar] Building jar: [Temp]/hello.jar
diff --git a/compiler/testData/integration/ant/jvm/javacCompiler/build.log.expected b/compiler/testData/integration/ant/jvm/javacCompiler/build.log.expected
index 1ee5576831e..b0482150f40 100644
--- a/compiler/testData/integration/ant/jvm/javacCompiler/build.log.expected
+++ b/compiler/testData/integration/ant/jvm/javacCompiler/build.log.expected
@@ -3,7 +3,7 @@ Buildfile: [TestData]/build.xml
 
 build:
     [mkdir] Created dir: [Temp]/classes
-    [javac] Compiling 1 source file to [Temp]/classes
+    [javac] Compiling 2 source files to [Temp]/classes
     [javac] Compiling [[TestData]/root1] => [[Temp]/classes]
     [javac] Running javac...
       [jar] Building jar: [Temp]/hello.jar
diff --git a/compiler/testData/integration/ant/jvm/noClasspathGiven/build.log.expected b/compiler/testData/integration/ant/jvm/noClasspathGiven/build.log.expected
index 43571e1ce89..32882961591 100644
--- a/compiler/testData/integration/ant/jvm/noClasspathGiven/build.log.expected
+++ b/compiler/testData/integration/ant/jvm/noClasspathGiven/build.log.expected
@@ -3,7 +3,7 @@ Buildfile: [TestData]/build.xml
 
 build:
     [mkdir] Created dir: [Temp]/classes
-    [javac] Compiling 1 source file to [Temp]/classes
+    [javac] Compiling 2 source files to [Temp]/classes
     [javac] Compiling [[TestData]] => [[Temp]/classes]
     [javac] Running javac...
       [jar] Building jar: [Temp]/hello.jar
diff --git a/compiler/testData/integration/ant/jvm/withKotlinNoJavaSources/build.log.expected b/compiler/testData/integration/ant/jvm/withKotlinNoJavaSources/build.log.expected
new file mode 100644
index 00000000000..43571e1ce89
--- /dev/null
+++ b/compiler/testData/integration/ant/jvm/withKotlinNoJavaSources/build.log.expected
@@ -0,0 +1,14 @@
+OUT:
+Buildfile: [TestData]/build.xml
+
+build:
+    [mkdir] Created dir: [Temp]/classes
+    [javac] Compiling 1 source file to [Temp]/classes
+    [javac] Compiling [[TestData]] => [[Temp]/classes]
+    [javac] Running javac...
+      [jar] Building jar: [Temp]/hello.jar
+
+BUILD SUCCESSFUL
+Total time: [time]
+
+Return code: 0
diff --git a/compiler/testData/integration/ant/jvm/withKotlinNoJavaSources/build.xml b/compiler/testData/integration/ant/jvm/withKotlinNoJavaSources/build.xml
new file mode 100644
index 00000000000..3b3c222aab9
--- /dev/null
+++ b/compiler/testData/integration/ant/jvm/withKotlinNoJavaSources/build.xml
@@ -0,0 +1,13 @@
+<project name="Ant Task Test" default="build">
+    <taskdef resource="org/jetbrains/kotlin/ant/antlib.xml" classpath="${kotlin.lib}/kotlin-ant.jar"/>
+
+    <target name="build">
+        <mkdir dir="${temp}/classes"/>
+        <javac srcdir="${test.data}" destdir="${temp}/classes" includeantruntime="false">
+            <withKotlin/>
+        </javac>
+        <jar destfile="${temp}/hello.jar">
+            <fileset dir="${temp}/classes"/>
+        </jar>
+    </target>
+</project>
diff --git a/compiler/testData/integration/ant/jvm/withKotlinNoJavaSources/hello.kt b/compiler/testData/integration/ant/jvm/withKotlinNoJavaSources/hello.kt
new file mode 100644
index 00000000000..6c9ab7fe60a
--- /dev/null
+++ b/compiler/testData/integration/ant/jvm/withKotlinNoJavaSources/hello.kt
@@ -0,0 +1,5 @@
+package hello
+
+fun main(args: Array<String>) {
+    println("Hello!")
+}
diff --git a/compiler/testData/integration/ant/jvm/withKotlinNoJavaSources/hello.run.expected b/compiler/testData/integration/ant/jvm/withKotlinNoJavaSources/hello.run.expected
new file mode 100644
index 00000000000..fd58d467c30
--- /dev/null
+++ b/compiler/testData/integration/ant/jvm/withKotlinNoJavaSources/hello.run.expected
@@ -0,0 +1,4 @@
+OUT:
+Hello!
+
+Return code: 0
diff --git a/compiler/tests/org/jetbrains/kotlin/integration/AntTaskJvmTest.java b/compiler/tests/org/jetbrains/kotlin/integration/AntTaskJvmTest.java
index bdbddd380c7..236db6c4946 100644
--- a/compiler/tests/org/jetbrains/kotlin/integration/AntTaskJvmTest.java
+++ b/compiler/tests/org/jetbrains/kotlin/integration/AntTaskJvmTest.java
@@ -101,6 +101,11 @@ public class AntTaskJvmTest extends AntTaskBaseTest {
         doJvmAntTest();
     }
 
+    @Test
+    public void withKotlinNoJavaSources() throws Exception {
+        doJvmAntTest();
+    }
+
     @Test
     public void javacCompiler() throws Exception {
         doJvmAntTest("-cp", getClassPathForAnt(),