diff --git a/.gitignore b/.gitignore
index f4ee33b..ec0247b 100644
--- a/.gitignore
+++ b/.gitignore
@@ -1,2 +1,3 @@
 /java-runtime-decompiler-2.0.tar.gz
 /java-runtime-decompiler-3.0.tar.gz
+/java-runtime-decompiler-4.0.tar.gz
diff --git a/java-runtime-decompiler b/java-runtime-decompiler
index e2b83b0..56fd9ab 100644
--- a/java-runtime-decompiler
+++ b/java-runtime-decompiler
@@ -82,5 +82,5 @@ else
 	echo "Agent was not found and agent path was not set correctly. This has to be done manually in the decompiler GUI, or set AGENT_PATH===path_to_agent_jar in the configuration file: $CONFIG_FILE" >&2
 fi
 
-run  "$@"
-
+export FLAGS="$FLAGS -Djdk.attach.allowAttachSelf=true"
+run   "$@"
diff --git a/java-runtime-decompiler.spec b/java-runtime-decompiler.spec
index ab60218..450a4b4 100644
--- a/java-runtime-decompiler.spec
+++ b/java-runtime-decompiler.spec
@@ -1,7 +1,7 @@
 Summary: Application for extraction and decompilation of JVM byte code
 Name: java-runtime-decompiler
-Version: 3.0
-Release: 9%{?dist}
+Version: 4.0
+Release: 1%{?dist}
 License: GPLv3
 URL: https://github.com/pmikova/java-runtime-decompiler
 Source0: https://github.com/pmikova/%{name}/archive/%{name}-%{version}.tar.gz
@@ -24,10 +24,10 @@ BuildRequires: maven-surefire-provider-junit5
 BuildRequires: maven-surefire
 BuildRequires: maven-surefire-plugin
 # depends on devel, not runtime (needs tools.jar)
-BuildRequires: java-1.8.0-devel
+BuildRequires: java-11-devel
 BuildRequires: google-gson
 BuildRequires: desktop-file-utils
-Requires: java-1.8.0-devel
+Requires: java-11-devel
 Recommends: fernflower
 Recommends: procyon-decompiler
 
@@ -49,10 +49,13 @@ This package contains the API documentation for %{name}.
 
 %build
 pushd runtime-decompiler
-%pom_remove_dep com.sun:tools
-%pom_add_dep com.sun:tools
+# not manipuling com.sun:tools in jdk11 phases
+#%%pom_remove_dep com.sun:tools
+#%%pom_add_dep com.sun:tools
 %pom_remove_plugin :maven-jar-plugin
 popd
+# seting up build jdk, as most likely we will build separate binary by jdk8
+export JAVA_HOME=/usr/lib/jvm/java-11-openjdk
 %mvn_build --xmvn-javadoc
 
 %install
@@ -89,6 +92,9 @@ desktop-file-install --vendor="fedora"                     \
 %license LICENSE
 
 %changelog
+* Tue Dec 08 2020 Jiri Vanek <jvanek@redhat.com> - 4.0-1
+- built by jdk11
+
 * Tue Jul 28 2020 Fedora Release Engineering <releng@fedoraproject.org> - 3.0-9
 - Rebuilt for https://fedoraproject.org/wiki/Fedora_33_Mass_Rebuild
 
diff --git a/sources b/sources
index d54d342..6cd7ade 100644
--- a/sources
+++ b/sources
@@ -1 +1 @@
-SHA512 (java-runtime-decompiler-3.0.tar.gz) = 329184689763b7777ef0bad1c0f787aa649f855692b52bd843cacd424d5d2c0caadad328f80cd7f229031a151b6414c712bd770abd285412055c5d34d932875c
+SHA512 (java-runtime-decompiler-4.0.tar.gz) = 073c3f2868ad82feee407626ed8a9962ff76ee49dc5feecd253a572d507c10c814112faeee8e1d3bf0007f8a95d7750ab6eadd845e54174e5695ca68df622764