diff --git a/.circleci/config.yml b/.circleci/config.yml
index a321671f..22f1b667 100644
--- a/.circleci/config.yml
+++ b/.circleci/config.yml
@@ -14,7 +14,7 @@ jobs:
     resource_class: large
     docker:
       # The primary container is an instance of the first list image listed. Your build commands run in this container.
-      - image: circleci/python:2.7
+      - image: circleci/python:3.6
     working_directory: ~/st2-packages
     environment:
       DISTROS: "xenial bionic el7 el8"
diff --git a/packages/st2/Makefile b/packages/st2/Makefile
index 7e3d2f2c..2cfe9617 100644
--- a/packages/st2/Makefile
+++ b/packages/st2/Makefile
@@ -23,6 +23,9 @@ endif
 ifeq ($(DEB_DISTRO),bionic)
 	PYTHON_BINARY := /usr/bin/python3
 	PIP_BINARY := pip
+else ifeq ($(DEB_DISTRO),xenial)
+	PYTHON_BINARY := /usr/bin/python3.6
+	PIP_BINARY := /usr/local/bin/pip3.6
 else ifeq ($(EL_VERSION),8)
 	PYTHON_BINARY := /usr/bin/python3
 	PIP_BINARY := /usr/local/bin/pip3
@@ -32,12 +35,12 @@ else ifeq ($(EL_VERSION),7)
 	PIP_BINARY := /usr/local/bin/pip3
 	PYTHON_ALT_BINARY := python3
 else
-	PYTHON_BINARY := python
-	PIP_BINARY := pip
-	PYTHON_ALT_BINARY := python
+	PYTHON_BINARY := /usr/bin/python3
+	PIP_BINARY := pip3
+	PYTHON_ALT_BINARY := python3
 endif
 
-	RUNNERS := $(shell ls ../contrib/runners)
+RUNNERS := $(shell ls ../contrib/runners)
 
 # Moved from top of file to handle when only py2 or py3 available
 ST2PKG_VERSION ?= $(shell $(PYTHON_BINARY) -c "from $(ST2_COMPONENT) import __version__; print(__version__),")
@@ -63,6 +66,7 @@ info:
 	@echo "EL_VERSION=$(EL_VERSION)"
 	@echo "DEB_DISTRO=$(DEB_DISTRO)"
 	@echo "PYTHON_BINARY=$(PYTHON_BINARY)"
+	@echo "PIP_BINARY=$(PIP_BINARY)"
 
 install: wheelhouse changelog
 
diff --git a/packages/st2/component.makefile b/packages/st2/component.makefile
index e2e2a205..7a752f60 100644
--- a/packages/st2/component.makefile
+++ b/packages/st2/component.makefile
@@ -22,6 +22,9 @@ endif
 ifeq ($(DEB_DISTRO),bionic)
 	PYTHON_BINARY := /usr/bin/python3
 	PIP_BINARY := /usr/bin/pip3
+else ifeq ($(DEB_DISTRO),xenial)
+	PYTHON_BINARY := /usr/bin/python3.6
+	PIP_BINARY := /usr/local/bin/pip3.6
 else ifeq ($(EL_VERSION),8)
 	PYTHON_BINARY := /usr/bin/python3
 	PIP_BINARY := /usr/local/bin/pip3
@@ -29,8 +32,9 @@ else ifeq ($(EL_VERSION),7)
 	PYTHON_BINARY := /usr/bin/python3
 	PIP_BINARY := /usr/local/bin/pip3
 else
-	PYTHON_BINARY := python
-	PIP_BINARY := pip
+	PYTHON_BINARY := /usr/bin/python3
+	PIP_BINARY := pip3
+	PYTHON_ALT_BINARY := python3
 endif
 
 # Moved from top of file to handle when only py2 or py3 available
@@ -62,9 +66,7 @@ populate_version: .stamp-populate_version
 
 requirements: .stamp-requirements
 .stamp-requirements:
-# Don't include Mistral runner for now, replace with commented version when mistral removed from st2
-#	$(PYTHON_BINARY) ../scripts/fixate-requirements.py -s in-requirements.txt -f ../fixed-requirements.txt
-	$(PYTHON_BINARY) ../scripts/fixate-requirements.py --skip=stackstorm-runner-mistral-v2,python-mistralclient -s in-requirements.txt -f ../fixed-requirements.txt
+	$(PYTHON_BINARY) ../scripts/fixate-requirements.py -s in-requirements.txt -f ../fixed-requirements.txt
 	cat requirements.txt
 
 wheelhouse: .stamp-wheelhouse
diff --git a/packages/st2/debian/rules b/packages/st2/debian/rules
index e494c7ab..d954c072 100755
--- a/packages/st2/debian/rules
+++ b/packages/st2/debian/rules
@@ -16,21 +16,20 @@ IS_SYSTEMD = $(shell command -v dh_systemd_enable > /dev/null 2>&1 && echo true)
 DEB_DISTRO := $(shell lsb_release -cs)
 
 # Xenial and Bionic depend on different libraries.
-# Most important, Bionic uses Python 3 and others use Python 2.7.
 ifeq ($(DEB_DISTRO),bionic)
 	BUILD_PRE_DEPENDS := python3 (>= 3.6)
 	BUILD_DEPENDS := python3-distutils, python3-dev
-else
-	BUILD_PRE_DEPENDS := python2.7
-	BUILD_DEPENDS := libpython-dev | python-dev
+else ifeq ($(DEB_DISTRO),xenial)
+	BUILD_PRE_DEPENDS := python3.6 (>= 3.6)
+	BUILD_DEPENDS := python3.6-dev
 endif
 
 %:
 # Use Python 3 binary on Ubuntu Bionic
 ifeq ($(DEB_DISTRO),bionic)
 	dh $@ --with python-virtualenv --python /usr/bin/python3
-else
-	dh $@ --with python-virtualenv
+else ifeq ($(DEB_DISTRO),xenial)
+	dh $@ --with python-virtualenv --python /usr/bin/python3.6
 endif
 
 override_dh_installdirs:
diff --git a/rake/spec/default/50-installed-cli-versions_spec.rb b/rake/spec/default/50-installed-cli-versions_spec.rb
index 475edd1b..2780748b 100644
--- a/rake/spec/default/50-installed-cli-versions_spec.rb
+++ b/rake/spec/default/50-installed-cli-versions_spec.rb
@@ -3,6 +3,7 @@
 describe 'st2 cli version checks' do
   describe command("st2 --version") do
     its(:exit_status) { is_expected.to eq 0 }
+    its(:stdout) { should match /on Python 3.6/ }
     # show version number in Rspec output
     after(:all) do
       puts puts "    " + described_class.stderr