diff --git a/src/mo_types/type.ml b/src/mo_types/type.ml
index 3c0b25609ff..2e0a6abf331 100644
--- a/src/mo_types/type.ml
+++ b/src/mo_types/type.ml
@@ -1420,8 +1420,8 @@ let canister_settings_typ =
 
 let wasm_memory_persistence_typ =
   sum [
-    ("Keep", unit);
-    ("Replace", unit);
+    ("keep", unit);
+    ("replace", unit);
   ]
 
 let upgrade_with_persistence_option_typ =
diff --git a/src/prelude/internals.mo b/src/prelude/internals.mo
index 713b7544ddb..b9fb873320b 100644
--- a/src/prelude/internals.mo
+++ b/src/prelude/internals.mo
@@ -401,8 +401,8 @@ module @ManagementCanister = {
 };
 
 type @WasmMemoryPersistence = {
-  #Keep;
-  #Replace;
+  #keep;
+  #replace;
 };
 
 type @UpgradeOptions = {
@@ -460,7 +460,7 @@ func @install_actor_helper(
       };
       case (#upgrade actor2) {
         let wasm_memory_persistence = if enhanced_orthogonal_persistence {
-          ?(#Keep)
+          ?(#keep)
         } else {
           null
         };
diff --git a/test/run-drun/actor-class-mgmt-enhanced.mo b/test/run-drun/actor-class-mgmt-enhanced.mo
index 17a82939001..730ad569bf4 100644
--- a/test/run-drun/actor-class-mgmt-enhanced.mo
+++ b/test/run-drun/actor-class-mgmt-enhanced.mo
@@ -123,7 +123,7 @@ actor a {
       assert (c5 == c4);
 
       let c6 = await
-        (system Cs.C)(#upgrade_with_persistence { wasm_memory_persistence = #Keep ; canister = c5 })(6, null);
+        (system Cs.C)(#upgrade_with_persistence { wasm_memory_persistence = #keep ; canister = c5 })(6, null);
       assert ({args = 6; upgrades = 3} == (await c6.observe()));
       assert (c6 == c5);
 
@@ -135,7 +135,7 @@ actor a {
 
       // no need to add cycles
       let c8 = await
-        (system Cs.C)(#upgrade_with_persistence { wasm_memory_persistence = #Replace ; canister = c7 })(8, null);
+        (system Cs.C)(#upgrade_with_persistence { wasm_memory_persistence = #replace ; canister = c7 })(8, null);
       assert ({args = 8; upgrades = 0} == (await c8.observe()));
       assert (c8 == c7);
 
diff --git a/test/run-drun/map-mixed-upgrades/map0.mo b/test/run-drun/map-mixed-upgrades/map0.mo
index 96ac9dea3a9..3a73ef81682 100644
--- a/test/run-drun/map-mixed-upgrades/map0.mo
+++ b/test/run-drun/map-mixed-upgrades/map0.mo
@@ -68,7 +68,7 @@ actor a {
          case null {};
          case (?n) {
            nodes[i] :=
-             ? (await (system Lib.Node)(#upgrade_with_persistence { wasm_memory_persistence = #Keep; canister = n })(i)); // upgrade!
+             ? (await (system Lib.Node)(#upgrade_with_persistence { wasm_memory_persistence = #keep; canister = n })(i)); // upgrade!
          }
        }
     }
@@ -80,7 +80,7 @@ actor a {
          case null {};
          case (?n) {
            nodes[i] :=
-             ? (await (system Lib.Node)(#upgrade_with_persistence { wasm_memory_persistence = #Replace; canister = n })(i)); // upgrade!
+             ? (await (system Lib.Node)(#upgrade_with_persistence { wasm_memory_persistence = #replace; canister = n })(i)); // upgrade!
          }
        }
     }
diff --git a/test/run-drun/map-mixed-upgrades/map1.mo b/test/run-drun/map-mixed-upgrades/map1.mo
index f85e7439064..60c7f00fc37 100644
--- a/test/run-drun/map-mixed-upgrades/map1.mo
+++ b/test/run-drun/map-mixed-upgrades/map1.mo
@@ -79,7 +79,7 @@ actor a {
          case null {};
          case (?n) {
            nodes[i] :=
-             ? (await (system Lib.Node)(#upgrade_with_persistence { wasm_memory_persistence = #Keep; canister = n })(i)); // upgrade!
+             ? (await (system Lib.Node)(#upgrade_with_persistence { wasm_memory_persistence = #keep; canister = n })(i)); // upgrade!
          }
        }
     }
@@ -91,7 +91,7 @@ actor a {
          case null {};
          case (?n) {
            nodes[i] :=
-             ? (await (system Lib.Node)(#upgrade_with_persistence { wasm_memory_persistence = #Replace; canister = n })(i)); // upgrade!
+             ? (await (system Lib.Node)(#upgrade_with_persistence { wasm_memory_persistence = #replace; canister = n })(i)); // upgrade!
          }
        }
     }
diff --git a/test/run-drun/migration-paths/new-installer.mo b/test/run-drun/migration-paths/new-installer.mo
index de73aae5e23..777fda0ab5d 100644
--- a/test/run-drun/migration-paths/new-installer.mo
+++ b/test/run-drun/migration-paths/new-installer.mo
@@ -19,7 +19,7 @@ actor {
         switch testCanister {
             case null Prim.trap("null canister");
             case (?canister) {
-                ignore await (system TestCanister.TestCanister)(#upgrade_with_persistence { wasm_memory_persistence = #Keep; canister })();
+                ignore await (system TestCanister.TestCanister)(#upgrade_with_persistence { wasm_memory_persistence = #keep; canister })();
                 Prim.debugPrint("Upgraded (keep main memory)");
             };
         };
@@ -29,7 +29,7 @@ actor {
         switch testCanister {
             case null Prim.trap("null canister");
             case (?canister) {
-                ignore await (system TestCanister.TestCanister)(#upgrade_with_persistence { wasm_memory_persistence = #Replace; canister })();
+                ignore await (system TestCanister.TestCanister)(#upgrade_with_persistence { wasm_memory_persistence = #replace; canister })();
                 Prim.debugPrint("Upgraded (replace main memory)");
             };
         };
diff --git a/test/run-drun/migration-paths/old-installer.mo b/test/run-drun/migration-paths/old-installer.mo
index 461e2f459e7..a5708fca3d7 100644
--- a/test/run-drun/migration-paths/old-installer.mo
+++ b/test/run-drun/migration-paths/old-installer.mo
@@ -31,7 +31,7 @@ actor installer {
          switch testCanister {
             case null Prim.trap("null canister");
             case (?canister) {
-                ignore await (system TestCanister.TestCanister)(#upgrade_with_persistence { wasm_memory_persistence =  #Keep; canister })();
+                ignore await (system TestCanister.TestCanister)(#upgrade_with_persistence { wasm_memory_persistence =  #keep; canister })();
                 Prim.debugPrint("Upgraded (keep main memory)");
             }
          }
@@ -41,7 +41,7 @@ actor installer {
          switch testCanister {
             case null Prim.trap("null canister");
             case (?canister) {
-                ignore await (system TestCanister.TestCanister)(#upgrade_with_persistence { wasm_memory_persistence = #Replace; canister })();
+                ignore await (system TestCanister.TestCanister)(#upgrade_with_persistence { wasm_memory_persistence = #replace; canister })();
                 Prim.debugPrint("Upgraded (replace main memory)");
             }
          }