diff --git a/.env.docker b/.env.docker
index 2ac31ed6a7..d88c6915a7 100644
--- a/.env.docker
+++ b/.env.docker
@@ -17,8 +17,11 @@ APP_KEY=${FF_APP_KEY}
 # Example: Europe/Amsterdam
 TZ=UTC
 
-# APP_URL and TRUSTED_PROXIES are useful when using Docker and/or a reverse proxy.
+# This variable must match your installation's external address but keep in mind that
+# it's only used on the command line as a fallback value.
 APP_URL=${APP_URL}
+
+# TRUSTED_PROXIES is a useful variable when using Docker and/or a reverse proxy.
 TRUSTED_PROXIES=${TRUSTED_PROXIES}
 
 # The log channel defines where your log entries go to.
diff --git a/.env.example b/.env.example
index 0daa6aee41..571115cda6 100644
--- a/.env.example
+++ b/.env.example
@@ -17,8 +17,11 @@ APP_KEY=SomeRandomStringOf32CharsExactly
 # Example: Europe/Amsterdam
 TZ=${TZ}
 
-# APP_URL and TRUSTED_PROXIES are useful when using Docker and/or a reverse proxy.
+# This variable must match your installation's external address but keep in mind that
+# it's only used on the command line as a fallback value.
 APP_URL=http://localhost
+
+# TRUSTED_PROXIES is a useful variable when using Docker and/or a reverse proxy.
 TRUSTED_PROXIES=
 
 # The log channel defines where your log entries go to.
diff --git a/.env.heroku b/.env.heroku
index 4925830036..972350d645 100644
--- a/.env.heroku
+++ b/.env.heroku
@@ -17,8 +17,11 @@ APP_KEY=7ahyYVPVsmxjdhsweWCauGeJfwc92NP2
 # Example: Europe/Amsterdam
 TZ=UTC
 
-# APP_URL and TRUSTED_PROXIES are useful when using Docker and/or a reverse proxy.
+# This variable must match your installation's external address but keep in mind that
+# it's only used on the command line as a fallback value.
 APP_URL=http://localhost
+
+# TRUSTED_PROXIES is a useful variable when using Docker and/or a reverse proxy.
 TRUSTED_PROXIES=
 
 # The log channel defines where your log entries go to.
diff --git a/.env.sandstorm b/.env.sandstorm
index 138001852b..ce73089fe8 100755
--- a/.env.sandstorm
+++ b/.env.sandstorm
@@ -17,8 +17,11 @@ APP_KEY=SomeRandomStringOf32CharsExactly
 # Example: Europe/Amsterdam
 TZ=UTC
 
-# APP_URL and TRUSTED_PROXIES are useful when using Docker and/or a reverse proxy.
+# This variable must match your installation's external address but keep in mind that
+# it's only used on the command line as a fallback value.
 APP_URL=http://localhost
+
+# TRUSTED_PROXIES is a useful variable when using Docker and/or a reverse proxy.
 TRUSTED_PROXIES=
 
 # The log channel defines where your log entries go to.
diff --git a/.env.testing b/.env.testing
index 94958107bb..27d1d955d5 100644
--- a/.env.testing
+++ b/.env.testing
@@ -17,8 +17,11 @@ APP_KEY=TestTestTestTestTestTestTestTest
 # Example: Europe/Amsterdam
 TZ=Europe/Amsterdam
 
-# APP_URL and TRUSTED_PROXIES are useful when using Docker and/or a reverse proxy.
+# This variable must match your installation's external address but keep in mind that
+# it's only used on the command line as a fallback value.
 APP_URL=http://localhost
+
+# TRUSTED_PROXIES is a useful variable when using Docker and/or a reverse proxy.
 TRUSTED_PROXIES=
 
 # The log channel defines where your log entries go to.