diff --git a/extension.js b/extension.js
index 027ceaf..b13952d 100644
--- a/extension.js
+++ b/extension.js
@@ -440,7 +440,7 @@ class Extension {
     // To make things deterministic during testing, we set the effect duration to 5
     // seconds.
     const duration =
-      testMode ? 7500 : this._settings.get_int(effect.getNick() + '-animation-time');
+      testMode ? 5000 : this._settings.get_int(effect.getNick() + '-animation-time');
 
     // All animations are relative to the window's center.
     actor.set_pivot_point(0.5, 0.5);
diff --git a/src/Doom.js b/src/Doom.js
index 61a9209..004a086 100644
--- a/src/Doom.js
+++ b/src/Doom.js
@@ -57,8 +57,8 @@ var Doom = class {
 
         // clang-format off
         shader.set_uniform_float(shader._uActorScale,      1, [testMode ? 1.0 : actorScale]);
-        shader.set_uniform_float(shader._uHorizontalScale, 1, [settings.get_double('doom-horizontal-scale')]);
-        shader.set_uniform_float(shader._uVerticalScale,   1, [testMode ? 500.0 : settings.get_double('doom-vertical-scale')]);
+        shader.set_uniform_float(shader._uHorizontalScale, 1, [testMode ? 50.0 :settings.get_double('doom-horizontal-scale')]);
+        shader.set_uniform_float(shader._uVerticalScale,   1, [testMode ? 150.0 : settings.get_double('doom-vertical-scale')]);
         shader.set_uniform_float(shader._uPixelSize,       1, [settings.get_int('doom-pixel-size')]);
         // clang-format on
       });
diff --git a/tests/generate-references.sh b/tests/generate-references.sh
index 7f00538..82df470 100755
--- a/tests/generate-references.sh
+++ b/tests/generate-references.sh
@@ -57,7 +57,7 @@ EXTENSION="burn-my-windows@schneegans.github.com"
 # All references images of the effects are captured at & cropped to this region
 # in the center of the screen. This is kind of arbitrary, but has been choosen so that
 # something is visible from each effect.
-CROP="100x100+910+480"
+CROP="100x100+900+500"
 
 # Run the container. For more info, visit https://github.com/Schneegans/gnome-shell-pod.
 POD=$(podman run --rm --cap-add=SYS_NICE --cap-add=IPC_LOCK -td "${IMAGE}")
@@ -110,7 +110,8 @@ capture_effect() {
   set_setting "open-preview-effect" "${1}"
   set_setting "close-preview-effect" "${1}"
 
-  do_in_pod gnome-extensions prefs "${EXTENSION}"
+  sleep 1
+  do_in_pod gnome-terminal
   sleep 3
   capture "tests/references/${1}-open-${SESSION}-${FEDORA_VERSION}.png"
   send_keystroke "Alt+F4"
@@ -132,6 +133,11 @@ podman cp "${EXTENSION}.zip" "${POD}:/home/gnomeshell"
 do_in_pod gnome-extensions install "${EXTENSION}.zip"
 
 
+# ----------------------- install gnome-terminal (this is used for testing the animations)
+
+do_in_pod sudo dnf install -y gnome-terminal
+
+
 # ---------------------------------------------------------------------- start GNOME Shell
 
 # Starting with GNOME 40, there is a "Welcome Tour" dialog popping up at first launch.
@@ -141,6 +147,9 @@ if [[ "${FEDORA_VERSION}" -gt 33 ]]; then
   do_in_pod gsettings set org.gnome.shell welcome-dialog-last-shown-version "999" || true
 fi
 
+# Make sure that new windows are opened in the center.
+do_in_pod gsettings set org.gnome.mutter center-new-windows true
+
 echo "Starting $(do_in_pod gnome-shell --version)."
 do_in_pod systemctl --user start "${SESSION}@:99"
 sleep 10
@@ -161,30 +170,36 @@ sleep 3
 
 # --------------------------------------------------------------------- capture the images
 
+# First we open the preferences and capture a portion of the dialog
+echo "Opening Preferences."
+do_in_pod gnome-extensions prefs "${EXTENSION}"
+sleep 3
+capture "tests/references/preferences-${SESSION}-${FEDORA_VERSION}.png"
+send_keystroke "Alt+F4"
+
 # The test mode ensures that the animations are "frozen" and do not change in time.
 echo "Entering test mode."
 set_setting "test-mode" true
-do_in_pod gsettings set org.gnome.mutter center-new-windows true
 
-capture_effect "energize-a"
-capture_effect "energize-b"
-capture_effect "fire"
-capture_effect "hexagon"
-capture_effect "incinerate"
-capture_effect "pixelate"
-capture_effect "tv"
-capture_effect "wisps"
+# capture_effect "energize-a"
+# capture_effect "energize-b"
+# capture_effect "fire"
+# capture_effect "hexagon"
+# capture_effect "incinerate"
+# capture_effect "pixelate"
+# capture_effect "tv"
+# capture_effect "wisps"
 
 if [[ "${FEDORA_VERSION}" -gt 32 ]]; then
-  capture_effect "apparition"
+  # capture_effect "apparition"
   capture_effect "doom"
 fi
 
-if [[ "${FEDORA_VERSION}" -gt 33 ]]; then
-  capture_effect "trex"
-  capture_effect "broken-glass"
-  capture_effect "matrix"
-  capture_effect "snap"
-fi
+# if [[ "${FEDORA_VERSION}" -gt 33 ]]; then
+#   capture_effect "trex"
+#   capture_effect "broken-glass"
+#   capture_effect "matrix"
+#   capture_effect "snap"
+# fi
 
 echo "All reference images generated successfully."
diff --git a/tests/run-test.sh b/tests/run-test.sh
index eb60011..5b28e76 100755
--- a/tests/run-test.sh
+++ b/tests/run-test.sh
@@ -119,6 +119,17 @@ compare_with_target() {
   fi
 }
 
+# This searches the virtual screen of the container for a given target image (first
+# parameter). If it is not found, an error message (second paramter) is printed and the
+# script exits via the fail() method above.
+find_target() {
+  echo "Searching for ${1} on the screen."
+  POS=$(do_in_pod find-target.sh "${1}") || true
+  if [[ -z "${POS}" ]]; then
+    fail "${2}"
+  fi
+}
+
 # This simulates the given keystroke in the container. Simply calling "xdotool key $1"
 # sometimes fails to be recognized. Maybe the default 12ms between key-down and key-up
 # are too short for xvfb...
@@ -145,15 +156,16 @@ test_effect() {
   set_setting "open-preview-effect" "${1}"
   set_setting "close-preview-effect" "${1}"
 
+  sleep 1
+  do_in_pod gnome-terminal
   sleep 3
-  do_in_pod gnome-extensions prefs "${EXTENSION}"
-  sleep 5
   compare_with_target "${1}-open-${SESSION}-${FEDORA_VERSION}.png" "Failed to test ${1} window open effect!"
   send_keystroke "Alt+F4"
-  sleep 5
+  sleep 3
   compare_with_target "${1}-close-${SESSION}-${FEDORA_VERSION}.png" "Failed to test ${1} window close effect!"
 }
 
+
 # ----------------------------------------------------- wait for the container to start up
 
 echo "Waiting for D-Bus."
@@ -167,6 +179,11 @@ podman cp "${EXTENSION}.zip" "${POD}:/home/gnomeshell"
 do_in_pod gnome-extensions install "${EXTENSION}.zip"
 
 
+# ----------------------- install gnome-terminal (this is used for testing the animations)
+
+do_in_pod sudo dnf install -y gnome-terminal
+
+
 # ---------------------------------------------------------------------- start GNOME Shell
 
 # Starting with GNOME 40, there is a "Welcome Tour" dialog popping up at first launch.
@@ -176,6 +193,9 @@ if [[ "${FEDORA_VERSION}" -gt 33 ]]; then
   do_in_pod gsettings set org.gnome.shell welcome-dialog-last-shown-version "999" || true
 fi
 
+# Make sure that new windows are opened in the center.
+do_in_pod gsettings set org.gnome.mutter center-new-windows true
+
 echo "Starting $(do_in_pod gnome-shell --version)."
 do_in_pod systemctl --user start "${SESSION}@:99"
 sleep 10
@@ -195,10 +215,17 @@ sleep 3
 
 # ---------------------------------------------------------------------- perform the tests
 
+# First we open the preferences and check whether the window is shown on screen by
+# searching for a small snippet of the preferences dialog.
+echo "Opening Preferences."
+do_in_pod gnome-extensions prefs "${EXTENSION}"
+sleep 3
+find_target "tests/references/preferences-${SESSION}-${FEDORA_VERSION}.png" "Failed to open preferences!"
+send_keystroke "Alt+F4"
+
 # The test mode ensures that the animations are "frozen" and do not change in time.
 echo "Entering test mode."
 set_setting "test-mode" true
-do_in_pod gsettings set org.gnome.mutter center-new-windows true
 
 test_effect "energize-a"
 test_effect "energize-b"