diff --git a/.gitignore b/.gitignore
index cecc3d8f4..0c5cc029c 100644
--- a/.gitignore
+++ b/.gitignore
@@ -23,3 +23,5 @@ __pycache__/
 parser.out
 parsetab.py
 .pytest_cache/
+compiler/src/prog8_kotlin.jar
+compiler/src/compiled_java
diff --git a/compiler/compiler.iml b/compiler/compiler.iml
index 9319f77cf..96f123a13 100644
--- a/compiler/compiler.iml
+++ b/compiler/compiler.iml
@@ -6,6 +6,9 @@
       <sourceFolder url="file://$MODULE_DIR$/src" isTestSource="false" />
       <sourceFolder url="file://$MODULE_DIR$/test" isTestSource="true" />
       <sourceFolder url="file://$MODULE_DIR$/res" type="java-resource" />
+      <excludeFolder url="file://$MODULE_DIR$/src/compiled_java" />
+      <excludeFolder url="file://$MODULE_DIR$/src/compiled_java/prog8" />
+      <excludeFolder url="file://$MODULE_DIR$/src/compiled_java/prog8/parser" />
     </content>
     <orderEntry type="inheritedJdk" />
     <orderEntry type="sourceFolder" forTests="false" />
diff --git a/compiler/src/build_the_compiler.cmd b/compiler/src/build_the_compiler.cmd
index 1906af2bb..c427774af 100644
--- a/compiler/src/build_the_compiler.cmd
+++ b/compiler/src/build_the_compiler.cmd
@@ -1,6 +1,6 @@
 mkdir compiled_java
 
-java -jar ../antlr/lib/antlr-4.7.1-complete.jar -o ./prog8/parser -no-listener -no-visitor -package prog8.parser ../antlr/prog8.g4
+java -jar ../antlr/lib/antlr-4.7.1-complete.jar -o ./prog8/parser -Xexact-output-dir -no-listener -no-visitor -package prog8.parser ../antlr/prog8.g4
 
 @dir /b /S src *.java > sources.txt
 javac  -verbose -d compiled_java -cp ../antlr/lib/antlr-runtime-4.7.1.jar @sources.txt
diff --git a/compiler/src/build_the_compiler.sh b/compiler/src/build_the_compiler.sh
index 481d74c30..824bcd9f3 100755
--- a/compiler/src/build_the_compiler.sh
+++ b/compiler/src/build_the_compiler.sh
@@ -1,5 +1,7 @@
 #!/usr/bin/env bash
 
+java -jar ../antlr/lib/antlr-4.7.1-complete.jar -o ./prog8/parser -Xexact-output-dir -no-listener -no-visitor -package prog8.parser ../antlr/prog8.g4
+
 find prog8 -name \*.java > javasources.txt
 mkdir -p compiled_java
 javac  -verbose -d compiled_java -cp ../antlr/lib/antlr-runtime-4.7.1.jar @javasources.txt