diff --git a/config/runtime.exs b/config/runtime.exs
index 22fdeb37e43f..fe8ff33802c1 100644
--- a/config/runtime.exs
+++ b/config/runtime.exs
@@ -246,14 +246,9 @@ data_dir = data_dir || persistent_cache_dir || System.get_env("DEFAULT_DATA_DIR"
 persistent_cache_dir = persistent_cache_dir || data_dir
 
 enable_email_verification =
-  config_dir
-  |> get_var_from_path_or_env("ENABLE_EMAIL_VERIFICATION", "false")
-  |> String.to_existing_atom()
+  get_bool_from_path_or_env(config_dir, "ENABLE_EMAIL_VERIFICATION", false)
 
-is_selfhost =
-  config_dir
-  |> get_var_from_path_or_env("SELFHOST", "true")
-  |> String.to_existing_atom()
+is_selfhost = get_bool_from_path_or_env(config_dir, "SELFHOST", true)
 
 # by default, registration is disabled in self-hosted setups
 disable_registration_default = to_string(is_selfhost)
@@ -274,15 +269,10 @@ custom_script_name =
   config_dir
   |> get_var_from_path_or_env("CUSTOM_SCRIPT_NAME", "script")
 
-disable_cron =
-  config_dir
-  |> get_var_from_path_or_env("DISABLE_CRON", "false")
-  |> String.to_existing_atom()
+disable_cron = get_bool_from_path_or_env(config_dir, "DISABLE_CRON", false)
 
 log_failed_login_attempts =
-  config_dir
-  |> get_var_from_path_or_env("LOG_FAILED_LOGIN_ATTEMPTS", "false")
-  |> String.to_existing_atom()
+  get_bool_from_path_or_env(config_dir, "LOG_FAILED_LOGIN_ATTEMPTS", false)
 
 websocket_url = get_var_from_path_or_env(config_dir, "WEBSOCKET_URL", "")
 
@@ -421,7 +411,7 @@ if config_env() in [:ce, :ce_dev, :ce_test] do
 end
 
 db_maybe_ipv6 =
-  if get_var_from_path_or_env(config_dir, "ECTO_IPV6") do
+  if get_bool_from_path_or_env(config_dir, "ECTO_IPV6") do
     if config_env() in [:ce, :ce_dev, :ce_test] do
       Logger.warning(
         "ECTO_IPV6 is no longer necessary as all TCP connections now try IPv6 automatically with IPv4 fallback"
@@ -522,9 +512,7 @@ config :plausible, Plausible.HelpScout,
 config :plausible, :imported,
   max_buffer_size: get_int_from_path_or_env(config_dir, "IMPORTED_MAX_BUFFER_SIZE", 10_000)
 
-maybe_ch_ipv6 =
-  get_var_from_path_or_env(config_dir, "ECTO_CH_IPV6", "false")
-  |> String.to_existing_atom()
+maybe_ch_ipv6 = get_bool_from_path_or_env(config_dir, "ECTO_CH_IPV6", false)
 
 if maybe_ch_ipv6 && config_env() in [:ce, :ce_dev, :ce_test] do
   Logger.warning(
@@ -632,27 +620,22 @@ case mailer_adapter do
       password: get_var_from_path_or_env(config_dir, "SMTP_USER_PWD"),
       tls: :if_available,
       allowed_tls_versions: [:tlsv1, :"tlsv1.1", :"tlsv1.2"],
-      ssl: get_var_from_path_or_env(config_dir, "SMTP_HOST_SSL_ENABLED") || false,
+      ssl: get_bool_from_path_or_env(config_dir, "SMTP_HOST_SSL_ENABLED", false),
       retries: get_var_from_path_or_env(config_dir, "SMTP_RETRIES") || 2,
-      no_mx_lookups: get_var_from_path_or_env(config_dir, "SMTP_MX_LOOKUPS_ENABLED") || true
+      no_mx_lookups: get_bool_from_path_or_env(config_dir, "SMTP_MX_LOOKUPS_ENABLED", true)
 
   "Bamboo.Mua" ->
     config :plausible, Plausible.Mailer, adapter: Bamboo.Mua
 
     # prevents common problems with Erlang's TLS v1.3
     middlebox_comp_mode =
-      get_var_from_path_or_env(config_dir, "SMTP_MIDDLEBOX_COMP_MODE", "false")
+      get_bool_from_path_or_env(config_dir, "SMTP_MIDDLEBOX_COMP_MODE", false)
 
-    middlebox_comp_mode = String.to_existing_atom(middlebox_comp_mode)
     config :plausible, Plausible.Mailer, ssl: [middlebox_comp_mode: middlebox_comp_mode]
 
     if relay = get_var_from_path_or_env(config_dir, "SMTP_HOST_ADDR") do
       port = get_int_from_path_or_env(config_dir, "SMTP_HOST_PORT", 587)
-
-      ssl_enabled =
-        if ssl_enabled = get_var_from_path_or_env(config_dir, "SMTP_HOST_SSL_ENABLED") do
-          String.to_existing_atom(ssl_enabled)
-        end
+      ssl_enabled = get_bool_from_path_or_env(config_dir, "SMTP_HOST_SSL_ENABLED")
 
       protocol =
         cond do
@@ -892,10 +875,7 @@ end
 
 config :tzdata, :data_dir, Path.join(persistent_cache_dir || System.tmp_dir!(), "tzdata_data")
 
-promex_disabled? =
-  config_dir
-  |> get_var_from_path_or_env("PROMEX_DISABLED", "true")
-  |> String.to_existing_atom()
+promex_disabled? = get_bool_from_path_or_env(config_dir, "PROMEX_DISABLED", true)
 
 config :plausible, Plausible.PromEx,
   disabled: promex_disabled?,
@@ -922,10 +902,7 @@ if not is_selfhost do
   config :plausible, Plausible.Site, default_ingest_threshold: site_default_ingest_threshold
 end
 
-s3_disabled? =
-  config_dir
-  |> get_var_from_path_or_env("S3_DISABLED", "true")
-  |> String.to_existing_atom()
+s3_disabled? = get_bool_from_path_or_env(config_dir, "S3_DISABLED", true)
 
 unless s3_disabled? do
   s3_env = [
diff --git a/lib/plausible/helpers/config.ex b/lib/plausible/helpers/config.ex
index aa28255d03f4..62853884f4be 100644
--- a/lib/plausible/helpers/config.ex
+++ b/lib/plausible/helpers/config.ex
@@ -23,4 +23,25 @@ defmodule Plausible.ConfigHelpers do
         end
     end
   end
+
+  def get_bool_from_path_or_env(config_dir, var_name, default \\ nil) do
+    case get_var_from_path_or_env(config_dir, var_name) do
+      nil -> default
+      var -> parse_bool(var)
+    end
+  end
+
+  defp parse_bool(var) do
+    case String.downcase(var) do
+      t when t in ["1", "t", "true", "y", "yes", "on"] ->
+        true
+
+      f when f in ["0", "f", "false", "n", "no", "off"] ->
+        false
+
+      _ ->
+        raise ArgumentError,
+              "Invalid boolean value: #{inspect(var)}. Expected one of: 1, 0, t, f, true, false, y, n, on, off"
+    end
+  end
 end