diff --git a/example/Makefile.inc b/example/Makefile.inc
index 789bdea80..8a51e1507 100644
--- a/example/Makefile.inc
+++ b/example/Makefile.inc
@@ -288,7 +288,7 @@ default_target: all
 
 # compile .gatt descriptions
 %.h: %.gatt
-	python ${BTSTACK_ROOT}/tool/compile_gatt.py $< $@
+	python3 ${BTSTACK_ROOT}/tool/compile_gatt.py $< $@
 
 # examples
 ant_test: ${CORE_OBJ} ${COMMON_OBJ} ${CLASSIC_OBJ} ant_test.c
diff --git a/port/qt-h4/CMakeLists.txt b/port/qt-h4/CMakeLists.txt
index 5f5476719..cd358b2bb 100644
--- a/port/qt-h4/CMakeLists.txt
+++ b/port/qt-h4/CMakeLists.txt
@@ -14,10 +14,10 @@ set(CMAKE_CXX_STANDARD_REQUIRED ON)
 message("${Qt5_DIR}")
 
 find_package(Qt5Core)
-include(FindPythonInterp)
+find_package(FindPython3)
 
 # BTstack Root
-set(BTSTACK_ROOT "../..")
+set(BTSTACK_ROOT "${PROJECT_SOURCE_DIR}/../..")
 message("BTSTACK_ROOT: ${BTSTACK_ROOT}")
 
 # BTstack include
diff --git a/tool/compile_gatt.py b/tool/compile_gatt.py
index 571b8b253..56a637747 100755
--- a/tool/compile_gatt.py
+++ b/tool/compile_gatt.py
@@ -1,4 +1,4 @@
-#!/usr/bin/env python
+#!/usr/bin/env python3
 #
 # BLE GATT configuration generator for use with BTstack
 # Copyright 2019 BlueKitchen GmbH