diff --git a/packages/playwright-core/src/protocol/serializers.ts b/packages/playwright-core/src/protocol/serializers.ts
index 3e1f99a41..813ab22cb 100644
--- a/packages/playwright-core/src/protocol/serializers.ts
+++ b/packages/playwright-core/src/protocol/serializers.ts
@@ -76,9 +76,9 @@ function innerParseSerializedValue(value: SerializedValue, handles: any[] | unde
   if (value.r !== undefined)
     return new RegExp(value.r.p, value.r.f);
   if (value.m !== undefined)
-    return new Map(Object.entries(JSON.parse(value.m)));
+    return new Map(Object.entries(innerParseSerializedValue(value.m, handles, refs)));
   if (value.se !== undefined)
-    return new Set(JSON.parse(value.se));
+    return new Set(innerParseSerializedValue(value.se, handles, refs));
 
   if (value.a !== undefined) {
     const result: any[] = [];
@@ -150,9 +150,9 @@ function innerSerializeValue(value: any, handleSerializer: (value: any) => Handl
     return { s: `${error.name}: ${error.message}\n${error.stack}` };
   }
   if (isMap(value))
-    return { m: JSON.stringify(Object.fromEntries(value)) };
+    return { m: innerSerializeValue(Object.fromEntries(value), handleSerializer, visitorInfo) };
   if (isSet(value))
-    return { se: JSON.stringify(Array.from(value)) };
+    return { se: innerSerializeValue(Array.from(value), handleSerializer, visitorInfo) };
   if (isDate(value))
     return { d: value.toJSON() };
   if (isURL(value))
diff --git a/packages/playwright-core/src/protocol/validator.ts b/packages/playwright-core/src/protocol/validator.ts
index 71f1ffbd0..c05a349a5 100644
--- a/packages/playwright-core/src/protocol/validator.ts
+++ b/packages/playwright-core/src/protocol/validator.ts
@@ -58,8 +58,8 @@ scheme.SerializedValue = tObject({
   d: tOptional(tString),
   u: tOptional(tString),
   bi: tOptional(tString),
-  m: tOptional(tString),
-  se: tOptional(tString),
+  m: tOptional(tType('SerializedValue')),
+  se: tOptional(tType('SerializedValue')),
   r: tOptional(tObject({
     p: tString,
     f: tString,
diff --git a/packages/playwright-core/src/server/isomorphic/utilityScriptSerializers.ts b/packages/playwright-core/src/server/isomorphic/utilityScriptSerializers.ts
index 9be8d04a3..90e4b913e 100644
--- a/packages/playwright-core/src/server/isomorphic/utilityScriptSerializers.ts
+++ b/packages/playwright-core/src/server/isomorphic/utilityScriptSerializers.ts
@@ -20,8 +20,8 @@ export type SerializedValue =
     { d: string } |
     { u: string } |
     { bi: string } |
-    { m: string } |
-    { se: string } |
+    { m: SerializedValue } |
+    { se: SerializedValue } |
     { r: { p: string, f: string} } |
     { a: SerializedValue[], id: number } |
     { o: { k: string, v: SerializedValue }[], id: number } |
@@ -105,9 +105,9 @@ export function source() {
       if ('bi' in value)
         return BigInt(value.bi);
       if ('m' in value)
-        return new Map(Object.entries(JSON.parse(value.m)));
+        return new Map(Object.entries(parseEvaluationResultValue(value.m)));
       if ('se' in value)
-        return new Set(JSON.parse(value.se));
+        return new Set(parseEvaluationResultValue(value.se));
       if ('r' in value)
         return new RegExp(value.r.p, value.r.f);
       if ('a' in value) {
@@ -178,9 +178,9 @@ export function source() {
       return { bi: value.toString() };
 
     if (isMap(value))
-      return { m: JSON.stringify(Object.fromEntries(value)) };
+      return { m: serialize(Object.fromEntries(value), handleSerializer, visitorInfo) };
     if (isSet(value))
-      return { se: JSON.stringify(Array.from(value)) };
+      return { se: serialize(Array.from(value), handleSerializer, visitorInfo) };
 
     if (isError(value)) {
       const error = value;
diff --git a/packages/protocol/src/channels.ts b/packages/protocol/src/channels.ts
index c57877321..9e7abcbd1 100644
--- a/packages/protocol/src/channels.ts
+++ b/packages/protocol/src/channels.ts
@@ -180,8 +180,8 @@ export type SerializedValue = {
   d?: string,
   u?: string,
   bi?: string,
-  m?: string,
-  se?: string,
+  m?: SerializedValue,
+  se?: SerializedValue,
   r?: {
     p: string,
     f: string,
diff --git a/packages/protocol/src/protocol.yml b/packages/protocol/src/protocol.yml
index bf7cd020e..72f4bf809 100644
--- a/packages/protocol/src/protocol.yml
+++ b/packages/protocol/src/protocol.yml
@@ -83,9 +83,9 @@ SerializedValue:
     # String representation of BigInt.
     bi: string?
     # String representation of Map.
-    m: string?
+    m: SerializedValue?
     # String representation of Set.
-    se: string?
+    se: SerializedValue?
     # Regular expression pattern and flags.
     r:
       type: object?