diff --git a/master_changes.md b/master_changes.md
index cfa455f6b39..ccd753beef6 100644
--- a/master_changes.md
+++ b/master_changes.md
@@ -107,6 +107,7 @@ users)
 ## Reftests
 ### Tests
   * Add some additional test to tree, for `--dev` && `--no-switch` [#5687 @rjbou]
+  * switch-set: add test that checks unsetting `OPAMSWITCH` when it was set by `opam env --set-switch` on an already set `OPAMSWITCH` variable in environment [#5742 rjbou]
 
 ### Engine
   * Set `SHELL` to `/bin/sh` in Windows to ensure `opam env` commands are consistent [#5723 @dra27]
diff --git a/src/client/opamConfigCommand.ml b/src/client/opamConfigCommand.ml
index 83bcca450f7..ccae3369d26 100644
--- a/src/client/opamConfigCommand.ml
+++ b/src/client/opamConfigCommand.ml
@@ -297,7 +297,15 @@ let ensure_env_aux ?(base=[]) ?(set_opamroot=false) ?(set_opamswitch=false)
         not (String.equal upd.envu_var "OPAM_LAST_ENV"))
       updates
   in
-  let last_env_file = write_last_env_file gt switch updates in
+  let last_env_file =
+    write_last_env_file gt switch
+      (* We remove OPAMSWITCH & OPAMROOT as they are not supposed
+         to be reverted *)
+      (List.filter (fun upd ->
+           not ((String.equal upd.envu_var "OPAMSWITCH")
+                || (String.equal upd.envu_var "OPAMROOT")))
+          updates)
+  in
   let updates =
     OpamStd.Option.map_default (fun target ->
         (env_update_resolved "OPAM_LAST_ENV" Eq
diff --git a/tests/reftests/switch-set.test b/tests/reftests/switch-set.test
index 5b674e54ee0..190d27eda42 100644
--- a/tests/reftests/switch-set.test
+++ b/tests/reftests/switch-set.test
@@ -75,3 +75,164 @@ Selecting opam switch -.
 Would select opam switch bar.
 ### opam switch show
 -
+### : OPAMSWITCH & OPAMROOT specific handling on last env storage and reverts :
+### opam sw create foo --empty
+### <set-switch.sh>
+unset `env | grep OPAM | cut -f 1 -d = | grep -v OPAMROOT | grep -v OPAMNOENVNOTICE`
+case $1 in
+  opam)
+    opam sw foo
+    ;;
+  env)
+    export OPAMSWITCH=foo
+    ;;
+esac
+echo "# current switch"
+opam sw show
+echo "# OPAMSWITCH current value"
+echo $OPAMSWITCH
+echo "# opam env"
+echo "$(opam env)" | grep OPAMSWITCH
+echo "# opam env with switch bar"
+echo "$(opam env --set-switch --sw bar)" | grep OPAMSWITCH
+eval $(opam env --set-switch --sw bar)
+echo "# OPAMSWITCH current value"
+echo $OPAMSWITCH
+echo "# opam env"
+echo "$(opam env)" | grep OPAMSWITCH
+echo "# OPAMSWITCH current value"
+echo $OPAMSWITCH
+echo "# current switch"
+opam sw show
+echo "# evaluate opam env"
+eval $(opam env)
+echo "# OPAMSWITCH current value"
+echo $OPAMSWITCH
+echo "# current switch"
+opam sw show
+### sh set-switch.sh opam
+# current switch
+foo
+# OPAMSWITCH current value
+
+# opam env
+# opam env with switch bar
+OPAMSWITCH='bar'; export OPAMSWITCH;
+# OPAMSWITCH current value
+bar
+# opam env
+# OPAMSWITCH current value
+bar
+# current switch
+bar
+# evaluate opam env
+# OPAMSWITCH current value
+bar
+# current switch
+bar
+### sh set-switch.sh env
+# current switch
+foo
+# OPAMSWITCH current value
+foo
+# opam env
+# opam env with switch bar
+OPAMSWITCH='bar'; export OPAMSWITCH;
+# OPAMSWITCH current value
+bar
+# opam env
+# OPAMSWITCH current value
+bar
+# current switch
+bar
+# evaluate opam env
+# OPAMSWITCH current value
+bar
+# current switch
+bar
+### opam init --bare --bypass-checks --root ./foo ./REPO -n | grep -v Cygwin
+No configuration file found, using built-in defaults.
+
+<><> Fetching repository information ><><><><><><><><><><><><><><><><><><><><><>
+[default] Initialised
+### opam switch create sw-foo --root ./foo --empty
+### opam init --bare --bypass-checks --root ./bar ./REPO -n | grep -v Cygwin
+No configuration file found, using built-in defaults.
+
+<><> Fetching repository information ><><><><><><><><><><><><><><><><><><><><><>
+[default] Initialised
+### opam switch create sw-bar --root ./bar --empty
+### <set-root.sh>
+unset `env | grep OPAM | cut -f 1 -d = | grep -v OPAMNOENVNOTICE`
+case $1 in
+  opam)
+    ARGF="--root foo"
+    ;;
+  env)
+    export OPAMROOT=${BASEDIR}/foo
+    ;;
+esac
+echo "# current root"
+opam var root $ARGF
+echo "# OPAMROOT current value"
+echo $OPAMROOT
+echo "# opam env"
+echo "$(opam env $ARGF)" | grep OPAMROOT
+echo "# opam env with root bar"
+echo "$(opam env --set-root --root ./bar)" | grep OPAMROOT
+eval $(opam env --set-root --root ./bar)
+echo "# OPAMROOT current value"
+echo $OPAMROOT
+echo "# opam env"
+echo "$(opam env)" | grep OPAMROOT
+echo "# OPAMROOT current value"
+echo $OPAMROOT
+echo "# current root"
+opam var root
+echo "evaluate opam env"
+eval $(opam env)
+echo "# OPAMROOT current value"
+echo $OPAMROOT
+echo "# current root"
+opam var root
+### sh set-root.sh opam
+# current root
+${BASEDIR}/foo
+# OPAMROOT current value
+
+# opam env
+[NOTE] To make opam select ${BASEDIR}/foo as its root in the current shell, add --set-root or set OPAMROOT
+# opam env with root bar
+OPAMROOT='${BASEDIR}/bar'; export OPAMROOT;
+# OPAMROOT current value
+${BASEDIR}/bar
+# opam env
+# OPAMROOT current value
+${BASEDIR}/bar
+# current root
+${BASEDIR}/bar
+evaluate opam env
+# OPAMROOT current value
+${BASEDIR}/bar
+# current root
+${BASEDIR}/bar
+### sh set-root.sh env
+# current root
+${BASEDIR}/foo
+# OPAMROOT current value
+${BASEDIR}/foo
+# opam env
+# opam env with root bar
+OPAMROOT='${BASEDIR}/bar'; export OPAMROOT;
+# OPAMROOT current value
+${BASEDIR}/bar
+# opam env
+# OPAMROOT current value
+${BASEDIR}/bar
+# current root
+${BASEDIR}/bar
+evaluate opam env
+# OPAMROOT current value
+${BASEDIR}/bar
+# current root
+${BASEDIR}/bar