diff --git a/Library/Homebrew/cmd/shellenv.sh b/Library/Homebrew/cmd/shellenv.sh
index 11c1f11852..4160362d97 100644
--- a/Library/Homebrew/cmd/shellenv.sh
+++ b/Library/Homebrew/cmd/shellenv.sh
@@ -3,20 +3,23 @@
 #:  Print export statements. When run in a shell, this installation of Homebrew will be added to your `PATH`, `MANPATH`, and `INFOPATH`.
 #:
 #:  The variables `HOMEBREW_PREFIX`, `HOMEBREW_CELLAR` and `HOMEBREW_REPOSITORY` are also exported to avoid querying them multiple times.
-#:  The variable `HOMEBREW_SHELLENV_SET` will be exported to avoid adding duplicate entries to the environment variables.
+#:  The variables and `HOMEBREW_SHELLENV_PREFIX` and `HOMEBREW_SHELLENV_SET` will be exported to avoid adding duplicate entries to the environment variables.
 #:  Consider adding evaluation of this command's output to your dotfiles (e.g. `~/.profile`, `~/.bash_profile`, or `~/.zprofile`) with: `eval $(brew shellenv)`
 
 # HOMEBREW_CELLAR and HOMEBREW_PREFIX are set by extend/ENV/super.rb
 # HOMEBREW_REPOSITORY is set by bin/brew
 # shellcheck disable=SC2154
 homebrew-shellenv() {
+  [[ "${HOMEBREW_SHELLENV_PREFIX}" == "${HOMEBREW_PREFIX}" ]] && return
+
   case "$(/bin/ps -p "${PPID}" -c -o comm=)" in
     fish | -fish)
       echo "set -gx HOMEBREW_PREFIX \"${HOMEBREW_PREFIX}\";"
       echo "set -gx HOMEBREW_CELLAR \"${HOMEBREW_CELLAR}\";"
       echo "set -gx HOMEBREW_REPOSITORY \"${HOMEBREW_REPOSITORY}\";"
-      [[ ":${HOMEBREW_SHELLENV_SET}:" == *":${HOMEBREW_PREFIX}:"* ]] && return
+      echo "set -gx HOMEBREW_SHELLENV_PREFIX \"${HOMEBREW_PREFIX}\";"
       echo "set -q PATH; or set PATH ''; set -gx PATH \"${HOMEBREW_PREFIX}/bin\" \"${HOMEBREW_PREFIX}/sbin\" \$PATH;"
+      [[ ":${HOMEBREW_SHELLENV_SET}:" == *":${HOMEBREW_PREFIX}:"* ]] && return
       echo "set -q MANPATH; or set MANPATH ''; set -gx MANPATH \"${HOMEBREW_PREFIX}/share/man\" \$MANPATH;"
       echo "set -q INFOPATH; or set INFOPATH ''; set -gx INFOPATH \"${HOMEBREW_PREFIX}/share/info\" \$INFOPATH;"
       echo "set -q HOMEBREW_SHELLENV_SET; or set HOMEBREW_SHELLENV_SET ''; set -gx HOMEBREW_SHELLENV_SET \"${HOMEBREW_PREFIX}\" \$HOMEBREW_SHELLENV_SET;"
@@ -25,8 +28,9 @@ homebrew-shellenv() {
       echo "setenv HOMEBREW_PREFIX ${HOMEBREW_PREFIX};"
       echo "setenv HOMEBREW_CELLAR ${HOMEBREW_CELLAR};"
       echo "setenv HOMEBREW_REPOSITORY ${HOMEBREW_REPOSITORY};"
-      [[ ":${HOMEBREW_SHELLENV_SET}:" == *":${HOMEBREW_PREFIX}:"* ]] && return
+      echo "setenv HOMEBREW_SHELLENV_PREFIX ${HOMEBREW_PREFIX};"
       echo "setenv PATH ${HOMEBREW_PREFIX}/bin:${HOMEBREW_PREFIX}/sbin:\$PATH;"
+      [[ ":${HOMEBREW_SHELLENV_SET}:" == *":${HOMEBREW_PREFIX}:"* ]] && return
       echo "setenv MANPATH ${HOMEBREW_PREFIX}/share/man\`[ \${?MANPATH} == 1 ] && echo \":\${MANPATH}\"\`:;"
       echo "setenv INFOPATH ${HOMEBREW_PREFIX}/share/info\`[ \${?INFOPATH} == 1 ] && echo \":\${INFOPATH}\"\`;"
       echo "setenv HOMEBREW_SHELLENV_SET ${HOMEBREW_PREFIX}\`[ \${?HOMEBREW_SHELLENV_SET} == 1 ] && echo \":\${HOMEBREW_SHELLENV_SET}\"\`;"
@@ -35,8 +39,9 @@ homebrew-shellenv() {
       echo "export HOMEBREW_PREFIX=\"${HOMEBREW_PREFIX}\";"
       echo "export HOMEBREW_CELLAR=\"${HOMEBREW_CELLAR}\";"
       echo "export HOMEBREW_REPOSITORY=\"${HOMEBREW_REPOSITORY}\";"
-      [[ ":${HOMEBREW_SHELLENV_SET}:" == *":${HOMEBREW_PREFIX}:"* ]] && return
+      echo "export HOMEBREW_SHELLENV_PREFIX=\"${HOMEBREW_PREFIX}\";"
       echo "export PATH=\"${HOMEBREW_PREFIX}/bin:${HOMEBREW_PREFIX}/sbin\${PATH+:\$PATH}\";"
+      [[ ":${HOMEBREW_SHELLENV_SET}:" == *":${HOMEBREW_PREFIX}:"* ]] && return
       echo "export MANPATH=\"${HOMEBREW_PREFIX}/share/man\${MANPATH+:\$MANPATH}:\";"
       echo "export INFOPATH=\"${HOMEBREW_PREFIX}/share/info:\${INFOPATH:-}\";"
       echo "export HOMEBREW_SHELLENV_SET=\"${HOMEBREW_PREFIX}\${HOMEBREW_SHELLENV_SET+:\$HOMEBREW_SHELLENV_SET}\";"
diff --git a/Library/Homebrew/env_config.rb b/Library/Homebrew/env_config.rb
index 95a5422055..1b90b4a9e7 100644
--- a/Library/Homebrew/env_config.rb
+++ b/Library/Homebrew/env_config.rb
@@ -305,9 +305,13 @@ module Homebrew
                      "useful to avoid long-running Homebrew commands being killed due to no output.",
         boolean:     true,
       },
+      HOMEBREW_SHELLENV_PREFIX:               {
+        description: "The lastest Homebrew prefix initialized by `brew shellenv`. If it is equal to " \
+                     "the current Homebrew prefix, `brew shellenv` will skip all export statements.",
+      },
       HOMEBREW_SHELLENV_SET:                  {
-        description: "A colon separated list of brew prefixes. If it is set and contains the current brew prefix, " \
-                     "`brew shellenv` skips export statements for paths.",
+        description: "A colon separated list of Homebrew prefixes. If it is set and contains the current " \
+                     "Homebrew prefix, `brew shellenv` will skip export statements for paths.",
       },
       all_proxy:                              {
         description: "Use this SOCKS5 proxy for `curl`(1), `git`(1) and `svn`(1) when downloading through Homebrew.",
diff --git a/docs/Manpage.md b/docs/Manpage.md
index 3d2cb825df..bbd89982ff 100644
--- a/docs/Manpage.md
+++ b/docs/Manpage.md
@@ -565,7 +565,7 @@ The search for *`text`* is extended online to `homebrew/core` and `homebrew/cask
 Print export statements. When run in a shell, this installation of Homebrew will be added to your `PATH`, `MANPATH`, and `INFOPATH`.
 
 The variables `HOMEBREW_PREFIX`, `HOMEBREW_CELLAR` and `HOMEBREW_REPOSITORY` are also exported to avoid querying them multiple times.
-The variable `HOMEBREW_SHELLENV_SET` will be exported to avoid adding duplicate entries to the environment variables.
+The variables and `HOMEBREW_SHELLENV_PREFIX` and `HOMEBREW_SHELLENV_SET` will be exported to avoid adding duplicate entries to the environment variables.
 Consider adding evaluation of this command's output to your dotfiles (e.g. `~/.profile`, `~/.bash_profile`, or `~/.zprofile`) with: `eval $(brew shellenv)`
 
 ### `tap` [*`options`*] [*`user`*`/`*`repo`*] [*`URL`*]
@@ -2088,8 +2088,11 @@ example, run `export HOMEBREW_NO_INSECURE_REDIRECT=1` rather than just
 - `HOMEBREW_VERBOSE_USING_DOTS`
   <br>If set, verbose output will print a `.` no more than once a minute. This can be useful to avoid long-running Homebrew commands being killed due to no output.
 
+- `HOMEBREW_SHELLENV_PREFIX`
+  <br>The lastest Homebrew prefix initialized by `brew shellenv`. If it is equal to the current Homebrew prefix, `brew shellenv` will skip all export statements.
+
 - `HOMEBREW_SHELLENV_SET`
-  <br>A colon separated list of brew prefixes. If it is set and contains the current brew prefix, `brew shellenv` skips export statements for paths.
+  <br>A colon separated list of Homebrew prefixes. If it is set and contains the current Homebrew prefix, `brew shellenv` will skip export statements for paths.
 
 - `all_proxy`
   <br>Use this SOCKS5 proxy for `curl`(1), `git`(1) and `svn`(1) when downloading through Homebrew.
diff --git a/manpages/brew.1 b/manpages/brew.1
index acecd9fab0..8167fbe694 100644
--- a/manpages/brew.1
+++ b/manpages/brew.1
@@ -784,7 +784,7 @@ Search for \fItext\fR in the given database\.
 Print export statements\. When run in a shell, this installation of Homebrew will be added to your \fBPATH\fR, \fBMANPATH\fR, and \fBINFOPATH\fR\.
 .
 .P
-The variables \fBHOMEBREW_PREFIX\fR, \fBHOMEBREW_CELLAR\fR and \fBHOMEBREW_REPOSITORY\fR are also exported to avoid querying them multiple times\. The variable \fBHOMEBREW_SHELLENV_SET\fR will be exported to avoid adding duplicate entries to the environment variables\. Consider adding evaluation of this command\'s output to your dotfiles (e\.g\. \fB~/\.profile\fR, \fB~/\.bash_profile\fR, or \fB~/\.zprofile\fR) with: \fBeval $(brew shellenv)\fR
+The variables \fBHOMEBREW_PREFIX\fR, \fBHOMEBREW_CELLAR\fR and \fBHOMEBREW_REPOSITORY\fR are also exported to avoid querying them multiple times\. The variables and \fBHOMEBREW_SHELLENV_PREFIX\fR and \fBHOMEBREW_SHELLENV_SET\fR will be exported to avoid adding duplicate entries to the environment variables\. Consider adding evaluation of this command\'s output to your dotfiles (e\.g\. \fB~/\.profile\fR, \fB~/\.bash_profile\fR, or \fB~/\.zprofile\fR) with: \fBeval $(brew shellenv)\fR
 .
 .SS "\fBtap\fR [\fIoptions\fR] [\fIuser\fR\fB/\fR\fIrepo\fR] [\fIURL\fR]"
 Tap a formula repository\.
@@ -3040,10 +3040,16 @@ If set, always assume \fB\-\-debug\fR when running commands\.
 If set, verbose output will print a \fB\.\fR no more than once a minute\. This can be useful to avoid long\-running Homebrew commands being killed due to no output\.
 .
 .TP
+\fBHOMEBREW_SHELLENV_PREFIX\fR
+.
+.br
+The lastest Homebrew prefix initialized by \fBbrew shellenv\fR\. If it is equal to the current Homebrew prefix, \fBbrew shellenv\fR will skip all export statements\.
+.
+.TP
 \fBHOMEBREW_SHELLENV_SET\fR
 .
 .br
-A colon separated list of brew prefixes\. If it is set and contains the current brew prefix, \fBbrew shellenv\fR skips export statements for paths\.
+A colon separated list of Homebrew prefixes\. If it is set and contains the current Homebrew prefix, \fBbrew shellenv\fR will skip export statements for paths\.
 .
 .TP
 \fBall_proxy\fR