diff --git a/master_changes.md b/master_changes.md
index 8fe7a426764..86269887bb3 100644
--- a/master_changes.md
+++ b/master_changes.md
@@ -61,6 +61,7 @@ users)
   * [BUG] When opam creates an empty variable then appends/prepends a value, ensure no additional separator is added [#5935 @dra27 - fix #5925]
   * [BUG] Fix `x-env-path-rewrite` splitting of values when reverting [#5935 @dra27 - fix #5838]
   * [BUG] Rework the logic of := and =: so that an empty entry is correctly preserved on multiple updates [#5935 @dra27 - fix #5926]
+  * [BUG] Fix incorrect reverting of `=+` and `=:` [#5935 @dra27 - fix #5926]
 
 ## Opamfile
 
diff --git a/src/state/opamEnv.ml b/src/state/opamEnv.ml
index e0cc8a44ee5..6922c9df87a 100644
--- a/src/state/opamEnv.ml
+++ b/src/state/opamEnv.ml
@@ -402,7 +402,7 @@ let reverse_env_update ~sepfmt var op arg cur_value =
   | EqPlus | Cygwin ->
     (match unzip_to ~sepfmt var arg (List.rev cur_value) with
      | None -> None
-     | Some (rl1, l2) -> Some (List.rev l2, List.rev rl1))
+     | Some (rl1, l2) -> Some (l2, List.rev rl1))
   | ColonEq ->
     (match unzip_to var ~sepfmt arg cur_value with
      | Some ([], [{ tr_entry = ""; _}]) -> Some ([], [])
@@ -410,7 +410,7 @@ let reverse_env_update ~sepfmt var op arg cur_value =
   | EqColon ->
     (match unzip_to ~sepfmt var arg (List.rev cur_value) with
      | Some ([], [{ tr_entry = ""; _}]) -> Some ([], [])
-     | Some (rl1, l2) -> Some (List.rev l2, List.rev rl1)
+     | Some (rl1, l2) -> Some (l2, List.rev rl1)
      | None -> None)
 
 let map_update_names env_keys updates =
diff --git a/tests/reftests/env.test b/tests/reftests/env.test
index b9ac0d6f6ea..9dd62d28083 100644
--- a/tests/reftests/env.test
+++ b/tests/reftests/env.test
@@ -273,15 +273,15 @@ NV_VARS_5925_8='': export NV_VARS_5925_8:
 NV_VARS_5926_L_1='': export NV_VARS_5926_L_1:
 NV_VARS_5926_L_2=':a': export NV_VARS_5926_L_2:
 NV_VARS_5926_L_3='': export NV_VARS_5926_L_3:
-NV_VARS_5926_L_4='a:': export NV_VARS_5926_L_4:
+NV_VARS_5926_L_4=':a': export NV_VARS_5926_L_4:
 NV_VARS_5926_L_5='': export NV_VARS_5926_L_5:
 NV_VARS_5926_L_6=':a': export NV_VARS_5926_L_6:
 NV_VARS_5926_L_7='': export NV_VARS_5926_L_7:
-NV_VARS_5926_L_8='a:': export NV_VARS_5926_L_8:
+NV_VARS_5926_L_8=':a': export NV_VARS_5926_L_8:
 NV_VARS_5926_M_1='a1::a2': export NV_VARS_5926_M_1:
-NV_VARS_5926_M_2='a2::a1': export NV_VARS_5926_M_2:
+NV_VARS_5926_M_2='a1::a2': export NV_VARS_5926_M_2:
 NV_VARS_5926_M_3='a1::a2': export NV_VARS_5926_M_3:
-NV_VARS_5926_M_4='a2::a1': export NV_VARS_5926_M_4:
+NV_VARS_5926_M_4='a1::a2': export NV_VARS_5926_M_4:
 NV_VARS_5926_S_1='': export NV_VARS_5926_S_1:
 NV_VARS_5926_S_2='': export NV_VARS_5926_S_2:
 NV_VARS_5926_S_3='': export NV_VARS_5926_S_3:
@@ -289,11 +289,11 @@ NV_VARS_5926_S_4='': export NV_VARS_5926_S_4:
 NV_VARS_5926_T_1='': export NV_VARS_5926_T_1:
 NV_VARS_5926_T_2='a:': export NV_VARS_5926_T_2:
 NV_VARS_5926_T_3='': export NV_VARS_5926_T_3:
-NV_VARS_5926_T_4=':a': export NV_VARS_5926_T_4:
+NV_VARS_5926_T_4='a:': export NV_VARS_5926_T_4:
 NV_VARS_5926_T_5='': export NV_VARS_5926_T_5:
 NV_VARS_5926_T_6='a:': export NV_VARS_5926_T_6:
 NV_VARS_5926_T_7='': export NV_VARS_5926_T_7:
-NV_VARS_5926_T_8=':a': export NV_VARS_5926_T_8:
+NV_VARS_5926_T_8='a:': export NV_VARS_5926_T_8:
 ### NV_VARS=/another/path
 ### NV_VARS2=/another/different/path
 ### NV_VARS3=/yet/another/different/path
@@ -384,15 +384,15 @@ NV_VARS_5925_8='': export NV_VARS_5925_8:
 NV_VARS_5926_L_1='': export NV_VARS_5926_L_1:
 NV_VARS_5926_L_2=':a': export NV_VARS_5926_L_2:
 NV_VARS_5926_L_3='': export NV_VARS_5926_L_3:
-NV_VARS_5926_L_4='a:': export NV_VARS_5926_L_4:
+NV_VARS_5926_L_4=':a': export NV_VARS_5926_L_4:
 NV_VARS_5926_L_5='': export NV_VARS_5926_L_5:
 NV_VARS_5926_L_6=':a': export NV_VARS_5926_L_6:
 NV_VARS_5926_L_7='': export NV_VARS_5926_L_7:
-NV_VARS_5926_L_8='a:': export NV_VARS_5926_L_8:
+NV_VARS_5926_L_8=':a': export NV_VARS_5926_L_8:
 NV_VARS_5926_M_1='a1::a2': export NV_VARS_5926_M_1:
-NV_VARS_5926_M_2='a2::a1': export NV_VARS_5926_M_2:
+NV_VARS_5926_M_2='a1::a2': export NV_VARS_5926_M_2:
 NV_VARS_5926_M_3='a1::a2': export NV_VARS_5926_M_3:
-NV_VARS_5926_M_4='a2::a1': export NV_VARS_5926_M_4:
+NV_VARS_5926_M_4='a1::a2': export NV_VARS_5926_M_4:
 NV_VARS_5926_S_1='': export NV_VARS_5926_S_1:
 NV_VARS_5926_S_2='': export NV_VARS_5926_S_2:
 NV_VARS_5926_S_3='': export NV_VARS_5926_S_3:
@@ -400,11 +400,11 @@ NV_VARS_5926_S_4='': export NV_VARS_5926_S_4:
 NV_VARS_5926_T_1='': export NV_VARS_5926_T_1:
 NV_VARS_5926_T_2='a:': export NV_VARS_5926_T_2:
 NV_VARS_5926_T_3='': export NV_VARS_5926_T_3:
-NV_VARS_5926_T_4=':a': export NV_VARS_5926_T_4:
+NV_VARS_5926_T_4='a:': export NV_VARS_5926_T_4:
 NV_VARS_5926_T_5='': export NV_VARS_5926_T_5:
 NV_VARS_5926_T_6='a:': export NV_VARS_5926_T_6:
 NV_VARS_5926_T_7='': export NV_VARS_5926_T_7:
-NV_VARS_5926_T_8=':a': export NV_VARS_5926_T_8:
+NV_VARS_5926_T_8='a:': export NV_VARS_5926_T_8:
 ### : Full revert of uninstalled package with setenv :
 ### <pkg:foo.1>
 opam-version: "2.0"