diff --git a/src/libraries/System.Text.Json/src/System/Text/Json/Serialization/Converters/Node/JsonObjectConverter.cs b/src/libraries/System.Text.Json/src/System/Text/Json/Serialization/Converters/Node/JsonObjectConverter.cs
index 3ba1988198cae1..7136d63dd3adde 100644
--- a/src/libraries/System.Text.Json/src/System/Text/Json/Serialization/Converters/Node/JsonObjectConverter.cs
+++ b/src/libraries/System.Text.Json/src/System/Text/Json/Serialization/Converters/Node/JsonObjectConverter.cs
@@ -103,8 +103,10 @@ internal static JsonObject ReadAsJsonNode(ref Utf8JsonReader reader, JsonNodeOpt
                 reader.Read(); // Move to the value token.
                 JsonNode? value = JsonNodeConverter.ReadAsJsonNode(ref reader, options);
 
-                // To have parity with the lazy JsonObject, we throw on duplicates.
-                jObject.Add(propertyName, value);
+                if (!jObject.TryAdd(propertyName, value))
+                {
+                    ThrowHelper.ThrowJsonException_DuplicatePropertyNotAllowed(propertyName);
+                }
             }
 
             // JSON is invalid so reader would have already thrown.
diff --git a/src/libraries/System.Text.Json/tests/System.Text.Json.Tests/JsonNode/JsonObjectTests.cs b/src/libraries/System.Text.Json/tests/System.Text.Json.Tests/JsonNode/JsonObjectTests.cs
index fdffaff5b6a0c9..f9d01d456c4d9c 100644
--- a/src/libraries/System.Text.Json/tests/System.Text.Json.Tests/JsonNode/JsonObjectTests.cs
+++ b/src/libraries/System.Text.Json/tests/System.Text.Json.Tests/JsonNode/JsonObjectTests.cs
@@ -1736,9 +1736,9 @@ private static void AssertDuplicatePropertyThrows<T>(string jsonPayload, bool is
             }
             else
             {
-                AssertExtensions.ThrowsContains<ArgumentException>(
+                AssertExtensions.ThrowsContains<JsonException>(
                     () => JsonSerializer.Deserialize<T>(jsonPayload, JsonTestSerializerOptions.DisallowDuplicateProperties),
-                    "An item with the same key has already been added.");
+                    "Duplicate property");
 
                 // Default options don't throw on deserialize but will throw when accessed
                 T node = JsonSerializer.Deserialize<T>(jsonPayload);
@@ -1756,14 +1756,14 @@ public static void JsonObject_DuplicatePropertyCaseInsensitiveThrows()
             string jsonPayload = """{"a":1,"A":2}""";
 
             _ = JsonSerializer.Deserialize<JsonObject>(jsonPayload); // Assert no throw
-            AssertExtensions.ThrowsContains<ArgumentException>(
+            AssertExtensions.ThrowsContains<JsonException>(
                 () => JsonSerializer.Deserialize<JsonObject>(jsonPayload, options),
-                "An item with the same key has already been added.");
+                "Duplicate property");
 
             _ = JsonSerializer.Deserialize<JsonNode>(jsonPayload); // Assert no throw
-            AssertExtensions.ThrowsContains<ArgumentException>(
+            AssertExtensions.ThrowsContains<JsonException>(
                 () => JsonSerializer.Deserialize<JsonNode>(jsonPayload, options),
-                "An item with the same key has already been added.");
+                "Duplicate property");
         }
 
         [Fact]
@@ -1774,14 +1774,14 @@ public static void JsonObject_NestedDuplicatePropertyCaseInsensitiveThrows()
             string jsonPayload = """[{"a":1,"A":2}]""";
 
             _ = JsonSerializer.Deserialize<JsonArray>(jsonPayload); // Assert no throw
-            AssertExtensions.ThrowsContains<ArgumentException>(
+            AssertExtensions.ThrowsContains<JsonException>(
                 () => JsonSerializer.Deserialize<JsonArray>(jsonPayload, options),
-                "An item with the same key has already been added.");
+                "Duplicate property");
 
             _ = JsonSerializer.Deserialize<JsonNode>(jsonPayload); // Assert no throw
-            AssertExtensions.ThrowsContains<ArgumentException>(
+            AssertExtensions.ThrowsContains<JsonException>(
                 () => JsonSerializer.Deserialize<JsonNode>(jsonPayload, options),
-                "An item with the same key has already been added.");
+                "Duplicate property");
         }
 
         [Theory]