diff --git a/Antlr4.Runtime/Misc/NotNullAttribute.cs b/Antlr4.Runtime/Misc/NotNullAttribute.cs
index 10549eb20..4f6fd8339 100644
--- a/Antlr4.Runtime/Misc/NotNullAttribute.cs
+++ b/Antlr4.Runtime/Misc/NotNullAttribute.cs
@@ -2,7 +2,7 @@
 {
     using System;
 
-    [AttributeUsage(AttributeTargets.Field | AttributeTargets.Parameter | AttributeTargets.ReturnValue, Inherited = true, AllowMultiple = false)]
+    [AttributeUsage(AttributeTargets.Field | AttributeTargets.Parameter | AttributeTargets.ReturnValue | AttributeTargets.Property, Inherited = true, AllowMultiple = false)]
     public sealed class NotNullAttribute : Attribute
     {
     }
diff --git a/Antlr4.Runtime/Misc/NullableAttribute.cs b/Antlr4.Runtime/Misc/NullableAttribute.cs
index 80b319710..b0037ece0 100644
--- a/Antlr4.Runtime/Misc/NullableAttribute.cs
+++ b/Antlr4.Runtime/Misc/NullableAttribute.cs
@@ -2,7 +2,7 @@
 {
     using System;
 
-    [AttributeUsage(AttributeTargets.Field | AttributeTargets.Parameter | AttributeTargets.ReturnValue, Inherited = true, AllowMultiple = false)]
+    [AttributeUsage(AttributeTargets.Field | AttributeTargets.Parameter | AttributeTargets.ReturnValue | AttributeTargets.Property, Inherited = true, AllowMultiple = false)]
     public sealed class NullableAttribute : Attribute
     {
     }