diff --git a/action.yml b/action.yml
index b2c0edc..aad041c 100644
--- a/action.yml
+++ b/action.yml
@@ -47,7 +47,7 @@ inputs:
   packageMode:
     required: false
     default: false
-    description: 'Whether the tests are being run for a Unity package. Not needed for packages located within a Unity Project.'
+    description: 'Whether the tests are being run for a Unity package instead of a Unity project. NOTE: If this is true, any custom docker image you pass must be compatible with apt-get.'
 outputs:
   artifactsPath:
     description: 'Path where the artifacts are stored'
diff --git a/dist/Dockerfile b/dist/Dockerfile
index b694818..f420b80 100644
--- a/dist/Dockerfile
+++ b/dist/Dockerfile
@@ -10,13 +10,6 @@ LABEL "repository"="http://github.com/webbertakken/unity-actions"
 LABEL "homepage"="http://github.com/webbertakken/unity-actions"
 LABEL "maintainer"="Webber Takken <webber@takken.io>"
 
-RUN apt-get update \
-&&  apt-get upgrade -y --force-yes \
-&&  apt-get install -y --force-yes \
-    jq \
-&&  apt-get clean \
-&&  rm -rf /var/cache/apt/archives/* /var/lib/apt/lists/*
-
 ADD steps /steps
 RUN chmod -R +x /steps
 ADD entrypoint.sh /entrypoint.sh
diff --git a/dist/entrypoint.sh b/dist/entrypoint.sh
index 7a266ad..aa32b19 100755
--- a/dist/entrypoint.sh
+++ b/dist/entrypoint.sh
@@ -7,6 +7,27 @@
 ACTIVATE_LICENSE_PATH="$GITHUB_WORKSPACE/_activate-license"
 mkdir -p "$ACTIVATE_LICENSE_PATH"
 
+#
+# Check if apt-get is available if in package mode (if not, we must abort since we need to install jq)
+#
+if [ "$PACKAGE_MODE" = "true" ]; then
+  echo "Running tests on a Unity package rather than a Unity project."
+  echo "Checking if apt-get is installed."
+  apt-get --version > /dev/null 2>&1
+  if [ $? -ne 0 ]; then
+    echo "apt-get is not installed. Aborting..."
+    exit
+  fi
+
+  # install jq
+  apt-get update \
+    &&  apt-get upgrade -y --force-yes \
+    &&  apt-get install -y --force-yes \
+        jq \
+    &&  apt-get clean \
+    &&  rm -rf /var/cache/apt/archives/* /var/lib/apt/lists/*
+fi
+
 #
 # Run steps
 #