diff --git a/.taskcluster.yml b/.taskcluster.yml
index bb1d1a60a..8ee9fc564 100644
--- a/.taskcluster.yml
+++ b/.taskcluster.yml
@@ -81,7 +81,7 @@ tasks:
             - tc-treeherder.v2.fenix.${head_rev}
           payload:
             maxRunTime: 600   # Decision should remain fast enough to schedule a handful of tasks
-            image: mozillamobile/fenix:1.3
+            image: mozillamobile/fenix:1.4
             command:
               - /bin/bash
               - --login
diff --git a/automation/docker/Dockerfile b/automation/docker/Dockerfile
index e1471e8d0..e11f95317 100644
--- a/automation/docker/Dockerfile
+++ b/automation/docker/Dockerfile
@@ -15,16 +15,25 @@ ENV GOOGLE_SDK_VERSION 233
 
 # -- System -----------------------------------------------------------------------------
 
-RUN apt-get update -qq
+RUN apt-get update -qq \
+    # We need to install tzdata before all of the other packages. Otherwise it will show an interactive dialog that
+    # we cannot navigate while building the Docker image.
+    && apt-get install -y tzdata \
+    && apt-get install -y openjdk-8-jdk \
+                          wget \
+                          expect \
+                          git \
+                          curl \
+                          python \
+                          python-pip \
+                          locales \
+                          unzip \
+    && apt-get clean
 
-RUN apt-get install -y openjdk-8-jdk \
-					   curl \
-					   wget \
-					   git \
-					   python \
-					   python-pip \
-					   locales \
-					   unzip
+RUN pip install --upgrade pip
+RUN pip install 'taskcluster>=4,<5'
+RUN pip install arrow
+RUN pip install pyyaml
 
 RUN locale-gen en_US.UTF-8
 
@@ -47,19 +56,8 @@ RUN touch /opt/android-sdk/.android/repositories.cfg
 
 RUN yes | sdkmanager --licenses
 
-RUN sdkmanager --verbose "platform-tools" \
-    "platforms;android-28" \
-    "build-tools;${ANDROID_BUILD_TOOLS}" \
-    "extras;android;m2repository" \
-    "extras;google;m2repository"
-
 # Checkout source code
-#RUN git clone https://github.com/mozilla-mobile/fenix.git
-RUN git clone https://github.com/rpappalax/fenix.git -b dockerfile-add-test-deps --single-branch
-
-# Build project and run gradle tasks once to pull all dependencies
-WORKDIR /opt/fenix
-RUN ./gradlew -PversionName=0.0 --no-daemon assemble test lint
+RUN git clone https://github.com/mozilla-mobile/fenix.git
 
 # -- Test tools -------------------------------------------------------------------------
 
@@ -81,15 +79,7 @@ RUN URL_FLANK_BIN=$(curl -s "https://api.github.com/repos/TestArmada/flank/relea
     && wget "https:${URL_FLANK_BIN}" -O ${TEST_TOOLS}/flank.jar \
     && chmod +x ${TEST_TOOLS}/flank.jar
 
-# -- Post setup -------------------------------------------------------------------------
-
-# Install taskcluster python library (used by decision tasks)
-# 5.0.0 is still incompatible with taskclusterProxy, meaning no decision task is able
-# to schedule the rest of the Taskcluster tasks. Please upgrade to taskcluster>=5 once
-# https://bugzilla.mozilla.org/show_bug.cgi?id=1460015 is fixed
-RUN pip install 'taskcluster>=4,<5'
-RUN pip install arrow
-
-# -- Cleanup ----------------------------------------------------------------------------
-
-RUN apt-get clean
+# Build project and run gradle tasks once to pull all dependencies
+WORKDIR /opt/fenix
+RUN ./gradlew -PversionName=0.0 --no-daemon assemble test lint \
+    && ./gradlew clean
\ No newline at end of file
diff --git a/gradle.properties b/gradle.properties
index 14194767b..ea86ad3c4 100644
--- a/gradle.properties
+++ b/gradle.properties
@@ -6,7 +6,7 @@
 # http://www.gradle.org/docs/current/userguide/build_environment.html
 # Specifies the JVM arguments used for the daemon process.
 # The setting is particularly useful for tweaking memory settings.
-org.gradle.jvmargs=-Xmx2048m
+org.gradle.jvmargs=-Xmx4096m
 # When configured, Gradle will run in incubating parallel mode.
 # This option should only be used with decoupled projects. More details, visit
 # http://www.gradle.org/docs/current/userguide/multi_project_builds.html#sec:decoupled_projects