diff --git a/bin/brew b/bin/brew
index 5fb806e894..6e44162597 100755
--- a/bin/brew
+++ b/bin/brew
@@ -19,6 +19,13 @@ then
   exit 1
 fi
 
+# Fail fast with concise message when HOME is unset
+if [[ -z "${HOME:-}" ]]
+then
+  echo "Error: \$HOME must be set to run brew." >&2
+  exit 1
+fi
+
 quiet_cd() {
   cd "$@" &>/dev/null || return
 }
@@ -107,28 +114,8 @@ export_homebrew_env_file "${HOMEBREW_PREFIX}/etc/homebrew/brew.env"
 if [[ -n "${XDG_CONFIG_HOME-}" ]]
 then
   HOMEBREW_USER_CONFIG_HOME="${XDG_CONFIG_HOME}/homebrew"
-elif [[ -n "${HOME-}" ]]
-then
-  HOMEBREW_USER_CONFIG_HOME="${HOME}/.homebrew"
-elif [[ -n "${USER-}" ]]
-then
-  if [[ "${OSTYPE}" == "darwin"* ]]
-  then
-    HOMEBREW_USER_CONFIG_HOME="/Users/${USER}/.homebrew"
-  else
-    HOMEBREW_USER_CONFIG_HOME="/home/${USER}/.homebrew"
-  fi
-elif [[ -n "${LOGNAME-}" ]]
-then
-  if [[ "${OSTYPE}" == "darwin"* ]]
-  then
-    HOMEBREW_USER_CONFIG_HOME="/Users/${LOGNAME}/.homebrew"
-  else
-    HOMEBREW_USER_CONFIG_HOME="/home/${LOGNAME}/.homebrew"
-  fi
 else
-  echo "Error: \$HOME or \$USER or \$LOGNAME must be set to run brew." >&2
-  exit 1
+  HOMEBREW_USER_CONFIG_HOME="${HOME}/.homebrew"
 fi
 
 export_homebrew_env_file "${HOMEBREW_USER_CONFIG_HOME}/brew.env"