diff --git a/scripts/docker-install-phase1.bash b/scripts/docker-install-phase1.bash
index 08a3745..e7e5bdd 100755
--- a/scripts/docker-install-phase1.bash
+++ b/scripts/docker-install-phase1.bash
@@ -40,7 +40,5 @@ deb https://dl.yarnpkg.com/debian/ stable main
 deb https://downloads.ceylon-lang.org/apt/ unstable main
 EOF
 
-add-apt-repository -y -n ppa:deadsnakes/ppa
-
 popd >/dev/null
 rm "$0"
diff --git a/scripts/docker-install-phase3c.bash b/scripts/docker-install-phase3c.bash
index f8b7e0e..361a208 100755
--- a/scripts/docker-install-phase3c.bash
+++ b/scripts/docker-install-phase3c.bash
@@ -17,10 +17,6 @@ m4
 # MariaDB
 libtinfo5
 
-# Mathics
-python3.7
-python3.7-dev
-
 # MiniZinc
 minizinc
 
diff --git a/scripts/docker-install-phase3d.bash b/scripts/docker-install-phase3d.bash
index ec2a290..5d91cac 100755
--- a/scripts/docker-install-phase3d.bash
+++ b/scripts/docker-install-phase3d.bash
@@ -84,7 +84,8 @@ vim
 mono-vbnc
 
 # Wolfram Language
-python3.7
+python3
+python3-dev
 
 # x86
 clang
diff --git a/scripts/docker-install-phase5.bash b/scripts/docker-install-phase5.bash
index a16d73d..7ebecdd 100755
--- a/scripts/docker-install-phase5.bash
+++ b/scripts/docker-install-phase5.bash
@@ -126,7 +126,7 @@ npm install -g vim-language-server
 pip3 install whitespace
 
 # Wolfram Language
-python3.7 -m pip install mathics
+pip3 install Mathics3
 
 rm -rf /root/.cache /root/.config /root/.cpan /root/.cpanm /root/.dub /root/.gem /root/.npm /root/.npmrc
 rm -f /tmp/core-js-banners