diff --git a/zio-http/shared/src/main/scala/zio/http/endpoint/openapi/JsonSchema.scala b/zio-http/shared/src/main/scala/zio/http/endpoint/openapi/JsonSchema.scala
index 22cd74e241..f9b957b244 100644
--- a/zio-http/shared/src/main/scala/zio/http/endpoint/openapi/JsonSchema.scala
+++ b/zio-http/shared/src/main/scala/zio/http/endpoint/openapi/JsonSchema.scala
@@ -387,7 +387,7 @@ object JsonSchema {
                     Chunk.empty,
                   ),
                   ref,
-                  nested.children + (nested.rootRef.get -> nested.root),
+                  nested.children ++ (nested.rootRef.map(_ -> nested.root)),
                 )
               }
             case Schema.Set(elementSchema, _)               =>
diff --git a/zio-http/shared/src/test/scala/zio/http/endpoint/openapi/OpenAPISpec.scala b/zio-http/shared/src/test/scala/zio/http/endpoint/openapi/OpenAPISpec.scala
index da3ab41a08..e3ec7d73be 100644
--- a/zio-http/shared/src/test/scala/zio/http/endpoint/openapi/OpenAPISpec.scala
+++ b/zio-http/shared/src/test/scala/zio/http/endpoint/openapi/OpenAPISpec.scala
@@ -5,6 +5,9 @@ import scala.collection.immutable.ListMap
 import zio.json.ast.Json
 import zio.test._
 
+import zio.schema.Schema
+
+import zio.http.endpoint.openapi.JsonSchema.SchemaStyle
 import zio.http.endpoint.openapi.OpenAPI.SecurityScheme._
 
 object OpenAPISpec extends ZIOSpecDefault {
@@ -60,5 +63,20 @@ object OpenAPISpec extends ZIOSpecDefault {
 
       assertTrue(toJsonAst(json) == toJsonAst(expected))
     },
+    test("JsonSchema.fromZSchemaMulti correctly handles Map schema with List as Value") {
+      val schema           = Schema.map[String, List[String]]
+      val sch: JsonSchemas = JsonSchema.fromZSchemaMulti(schema, SchemaStyle.Reference)
+
+      val isSchemaProperlyGenerated = if (sch.root.isCollection) sch.root match {
+        case JsonSchema.Object(_, additionalProperties, _) =>
+          additionalProperties match {
+            case Right(JsonSchema.ArrayType(items)) => items.exists(_.isInstanceOf[JsonSchema.String])
+            case _                                  => false
+          }
+        case _                                             => false
+      }
+      else false
+      assertTrue(isSchemaProperlyGenerated)
+    },
   )
 }