diff --git a/lib-core.sh b/lib-core.sh
index b4f72ac..b21ec56 100755
--- a/lib-core.sh
+++ b/lib-core.sh
@@ -161,7 +161,7 @@ start_animation() {
 }
 
 stop_animation() {
-  kill -13 "${ANIM_PID}" &> /dev/null || true
+  [[ -e "/proc/${ANIM_PID}" ]] && kill -13 "${ANIM_PID}"
   setterm -cursor on
 }
 
@@ -468,7 +468,7 @@ rootify() {
   trap true SIGINT
   prompt -w "Executing '$(echo "${@}" | cut -c -35 )...' as root"
   sudo ${@} || operation_aborted
-  trap stop_animation SIGINT
+  trap signal_exit SIGINT
 }
 
 full_rootify() {
@@ -481,7 +481,7 @@ full_rootify() {
 userify() {
   trap true SIGINT
   sudo -u "${MY_USERNAME}" ${@} || operation_aborted
-  trap stop_animation SIGINT
+  trap signal_exit SIGINT
 }
 
 signal_exit() {
@@ -543,6 +543,7 @@ finalize_argument_parsing() {
     rm -rf "${WHITESUR_TMP_DIR}"; mkdir -p "${WHITESUR_TMP_DIR}"
     rm -rf "${THEME_SRC_DIR}/sass/_theme-options-temp.scss"
     exec 2> "${WHITESUR_TMP_DIR}/error_log.txt"
-    trap 'operation_aborted' ERR; trap 'signal_exit' SIGINT; trap 'signal_exit' EXIT
+    trap 'operation_aborted' ERR
+    trap 'signal_exit' INT EXIT TERM
   fi
 }
diff --git a/lib-install.sh b/lib-install.sh
index 22efb1f..13f20b5 100755
--- a/lib-install.sh
+++ b/lib-install.sh
@@ -439,17 +439,19 @@ install_firefox_theme() {
 }
 
 config_firefox() {
-  killall "firefox" &> /dev/null
+  killall "firefox" &> /dev/null || true
 
   for d in "${FIREFOX_DIR_HOME}/"*"default"*; do
-    rm -rf                                                                                      "${d}/chrome"
-    userify ln -sf "${FIREFOX_THEME_DIR}"                                                       "${d}/chrome"
-    userify_file                                                                                "${d}/prefs.js"
-    echo "user_pref(\"toolkit.legacyUserProfileCustomizations.stylesheets\", true);" >>         "${d}/prefs.js"
-    echo "user_pref(\"browser.tabs.drawInTitlebar\", true);" >>                                 "${d}/prefs.js"
-    echo "user_pref(\"browser.uidensity\", 0);" >>                                              "${d}/prefs.js"
-    echo "user_pref(\"layers.acceleration.force-enabled\", true);" >>                           "${d}/prefs.js"
-    echo "user_pref(\"mozilla.widget.use-argb-visuals\", true);" >>                             "${d}/prefs.js"
+    if [[ -f "${d}/prefs.js" ]]; then
+      rm -rf                                                                                    "${d}/chrome"
+      userify ln -sf "${FIREFOX_THEME_DIR}"                                                     "${d}/chrome"
+      userify_file                                                                              "${d}/prefs.js"
+      echo "user_pref(\"toolkit.legacyUserProfileCustomizations.stylesheets\", true);" >>       "${d}/prefs.js"
+      echo "user_pref(\"browser.tabs.drawInTitlebar\", true);" >>                               "${d}/prefs.js"
+      echo "user_pref(\"browser.uidensity\", 0);" >>                                            "${d}/prefs.js"
+      echo "user_pref(\"layers.acceleration.force-enabled\", true);" >>                         "${d}/prefs.js"
+      echo "user_pref(\"mozilla.widget.use-argb-visuals\", true);" >>                           "${d}/prefs.js"
+    fi
   done
 }