diff --git a/src/S_Core.bs.mjs b/src/S_Core.bs.mjs
index 52c47cb..5396fe9 100644
--- a/src/S_Core.bs.mjs
+++ b/src/S_Core.bs.mjs
@@ -438,7 +438,8 @@ function operationFn(s, o) {
   if ((o in s)) {
     return (s[o]);
   }
-  var f = compile(s.b, s, o);
+  var ss = o & 32 ? s.r() : s;
+  var f = compile(ss.b, ss, o);
   ((s[o] = f));
   return f;
 }
@@ -853,11 +854,10 @@ function serializeOrRaiseWith(value, schema) {
 }
 
 function serializeWith(value, schema) {
-  var schema$1 = schema.r();
   try {
     return {
             TAG: "Ok",
-            _0: operationFn(schema$1, 8)(value)
+            _0: operationFn(schema, 40)(value)
           };
   }
   catch (exn){
@@ -866,15 +866,14 @@ function serializeWith(value, schema) {
 }
 
 function serializeToUnknownOrRaiseWith(value, schema) {
-  return operationFn(schema.r(), 0)(value);
+  return operationFn(schema, 32)(value);
 }
 
 function serializeToUnknownWith(value, schema) {
-  var schema$1 = schema.r();
   try {
     return {
             TAG: "Ok",
-            _0: operationFn(schema$1, 0)(value)
+            _0: operationFn(schema, 32)(value)
           };
   }
   catch (exn){
@@ -938,11 +937,11 @@ function initialAssertOrRaise(unknown) {
 }
 
 function initialSerializeToUnknownOrRaise(unknown) {
-  return operationFn(this.r(), 0)(unknown);
+  return operationFn(this, 32)(unknown);
 }
 
 function initialSerializeOrRaise(unknown) {
-  return operationFn(this.r(), 8)(unknown);
+  return operationFn(this, 40)(unknown);
 }
 
 function jsParse(unknown) {
diff --git a/src/S_Core.res b/src/S_Core.res
index 500cae0..e5d7c58 100644
--- a/src/S_Core.res
+++ b/src/S_Core.res
@@ -431,6 +431,7 @@ module Operation = {
     @inline let assertOutput = 4
     @inline let jsonableOutput = 8
     @inline let jsonStringOutput = 16
+    @inline let reverse = 32
   }
 
   type t = int
@@ -865,7 +866,8 @@ let operationFn = (s, o) => {
   if %raw(`o in s`) {
     %raw(`s[o]`)
   } else {
-    let f = s.builder->Builder.compile(~schema=s, ~operation=o)
+    let ss = o->Operation.unsafeHasFlag(Operation.Flag.reverse) ? s.reverse() : s
+    let f = ss.builder->Builder.compile(~schema=ss, ~operation=o)
     let _ = %raw(`s[o] = f`)
     f
   }
@@ -1393,19 +1395,21 @@ let serializeOrRaiseWith = (value, schema) => {
 }
 
 let serializeWith = (value, schema) => {
-  schema.reverse()->useSyncOperation(
-    Operation.make()->Operation.addFlag(Operation.Flag.jsonableOutput),
+  schema->useSyncOperation(
+    Operation.make()
+    ->Operation.addFlag(Operation.Flag.reverse)
+    ->Operation.addFlag(Operation.Flag.jsonableOutput),
     value,
   )
 }
 
 @inline
 let serializeToUnknownOrRaiseWith = (value, schema) => {
-  (schema.reverse()->operationFn(Operation.make()))(value)
+  (schema->operationFn(Operation.make()->Operation.addFlag(Operation.Flag.reverse)))(value)
 }
 
 let serializeToUnknownWith = (value, schema) => {
-  schema.reverse()->useSyncOperation(Operation.make(), value)
+  schema->useSyncOperation(Operation.make()->Operation.addFlag(Operation.Flag.reverse), value)
 }
 
 let serializeToJsonStringOrRaiseWith = (value: 'value, schema: t<'value>, ~space=0): string => {
@@ -1462,13 +1466,15 @@ let initialAssertOrRaise = unknown => {
 }
 
 let initialSerializeToUnknownOrRaise = unknown => {
-  ((%raw(`this`)).reverse()->operationFn(Operation.make()))(unknown)
+  (%raw(`this`)->operationFn(Operation.make()->Operation.addFlag(Operation.Flag.reverse)))(unknown)
 }
 
 let initialSerializeOrRaise = unknown => {
   (
-    (%raw(`this`)).reverse()->operationFn(
-      Operation.make()->Operation.addFlag(Operation.Flag.jsonableOutput),
+    %raw(`this`)->operationFn(
+      Operation.make()
+      ->Operation.addFlag(Operation.Flag.jsonableOutput)
+      ->Operation.addFlag(Operation.Flag.reverse),
     )
   )(unknown)
 }