diff --git a/src/state/opamEnv.ml b/src/state/opamEnv.ml
index 07c4a8ad6b7..c9660eae7c5 100644
--- a/src/state/opamEnv.ml
+++ b/src/state/opamEnv.ml
@@ -369,7 +369,7 @@ 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 ([], [("", _, _)]) -> Some ([], [])
@@ -377,7 +377,7 @@ let reverse_env_update ~sepfmt var op arg cur_value =
   | EqColon ->
     (match unzip_to ~sepfmt var arg (List.rev cur_value) with
      | Some ([], [("", _, _)]) -> 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 e454ae85ba4..a9bbf009acd 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"