diff --git a/UAssetAPI.Tests/AssetUnitTests.cs b/UAssetAPI.Tests/AssetUnitTests.cs
index 2722f1b5..a9b28165 100644
--- a/UAssetAPI.Tests/AssetUnitTests.cs
+++ b/UAssetAPI.Tests/AssetUnitTests.cs
@@ -632,6 +632,18 @@ public void TestRepak()
             }
         }
 
+        /// <summary>
+        /// In this test, we parse a .usmap containing an OptionalProperty (as currently produced by Dumper-7) to verify compatibility.
+        /// </summary>
+        [TestMethod]
+        public void TestUsmapWithOptionalProperty()
+        {
+            var usmap = new Usmap(Path.Combine("TestAssets", "TestUE5_4", "BlankGame", "BlankGame_Dumper-7.usmap"));
+            Assert.AreEqual(31948, usmap.NameMap.Count);
+            Assert.AreEqual(1565, usmap.EnumMap.Count);
+            Assert.AreEqual(7657, usmap.Schemas.Count);
+        }
+
         public static MemoryStream PathToStream(string p)
         {
             using (FileStream origStream = File.Open(p, FileMode.Open, new FileInfo(p).IsReadOnly ? FileAccess.Read : FileAccess.ReadWrite))
diff --git a/UAssetAPI.Tests/TestAssets/TestUE5_4/BlankGame/BlankGame_Dumper-7.usmap b/UAssetAPI.Tests/TestAssets/TestUE5_4/BlankGame/BlankGame_Dumper-7.usmap
new file mode 100644
index 00000000..7aa579b5
Binary files /dev/null and b/UAssetAPI.Tests/TestAssets/TestUE5_4/BlankGame/BlankGame_Dumper-7.usmap differ
diff --git a/UAssetAPI.Tests/UAssetAPI.Tests.csproj b/UAssetAPI.Tests/UAssetAPI.Tests.csproj
index 29edf08a..faf3dddb 100644
--- a/UAssetAPI.Tests/UAssetAPI.Tests.csproj
+++ b/UAssetAPI.Tests/UAssetAPI.Tests.csproj
@@ -443,5 +443,8 @@
     <None Update="TestAssets\TestManyAssets\SnakePass\MP00_Intro.uasset">
       <CopyToOutputDirectory>Always</CopyToOutputDirectory>
     </None>
+    <None Update="TestAssets\TestUE5_4\BlankGame\BlankGame_Dumper-7.usmap">
+      <CopyToOutputDirectory>Always</CopyToOutputDirectory>
+    </None>
   </ItemGroup>
 </Project>
\ No newline at end of file
diff --git a/UAssetAPI/Unversioned/Usmap.cs b/UAssetAPI/Unversioned/Usmap.cs
index b5e7df8a..ab63ff03 100644
--- a/UAssetAPI/Unversioned/Usmap.cs
+++ b/UAssetAPI/Unversioned/Usmap.cs
@@ -92,6 +92,9 @@ public enum EPropertyType
         SetProperty,
         EnumProperty,
         FieldPathProperty,
+        OptionalProperty,
+        Utf8StrProperty,
+        AnsiStrProperty,
 
         Unknown = 0xFF
     };
@@ -906,6 +909,7 @@ private UsmapPropertyData InitPropData(EPropertyType typ)
                     return new UsmapStructData();
                 case EPropertyType.SetProperty:
                 case EPropertyType.ArrayProperty:
+                case EPropertyType.OptionalProperty:
                     return new UsmapArrayData(typ);
                 case EPropertyType.MapProperty:
                     return new UsmapMapData();
@@ -928,6 +932,7 @@ private UsmapPropertyData DeserializePropData(UsmapBinaryReader reader)
                     break;
                 case EPropertyType.SetProperty:
                 case EPropertyType.ArrayProperty:
+                case EPropertyType.OptionalProperty:
                     ((UsmapArrayData)res).InnerType = DeserializePropData(reader);
                     break;
                 case EPropertyType.MapProperty: