diff --git a/src/MemoryPack.Generator/DiagnosticDescriptors.cs b/src/MemoryPack.Generator/DiagnosticDescriptors.cs
index 50a77087..786831c9 100644
--- a/src/MemoryPack.Generator/DiagnosticDescriptors.cs
+++ b/src/MemoryPack.Generator/DiagnosticDescriptors.cs
@@ -57,9 +57,9 @@ internal static class DiagnosticDescriptors
         defaultSeverity: DiagnosticSeverity.Error,
         isEnabledByDefault: true);
 
-    public static readonly DiagnosticDescriptor OnMethodInUnamannagedType = new(
+    public static readonly DiagnosticDescriptor OnMethodInUnmanagedType = new(
         id: "MEMPACK008",
-        title: "MemoryPackObject's On*** methods can't annotate in unamnaged struct",
+        title: "MemoryPackObject's On*** methods can't annotate in unmanaged struct",
         messageFormat: "The MemoryPackable object '{0}' is unmanaged struct that can't annotate On***Attribute however '{1}' method annotaed",
         category: Category,
         defaultSeverity: DiagnosticSeverity.Error,
diff --git a/src/MemoryPack.Generator/MemoryPackGenerator.Parser.cs b/src/MemoryPack.Generator/MemoryPackGenerator.Parser.cs
index 0806cd14..8d74702d 100644
--- a/src/MemoryPack.Generator/MemoryPackGenerator.Parser.cs
+++ b/src/MemoryPack.Generator/MemoryPackGenerator.Parser.cs
@@ -397,7 +397,7 @@ public bool Validate(TypeDeclarationSyntax syntax, IGeneratorContext context, bo
 
             if (IsUnmanagedType)
             {
-                context.ReportDiagnostic(Diagnostic.Create(DiagnosticDescriptors.OnMethodInUnamannagedType, item.GetLocation(syntax), Symbol.Name, item.Name));
+                context.ReportDiagnostic(Diagnostic.Create(DiagnosticDescriptors.OnMethodInUnmanagedType, item.GetLocation(syntax), Symbol.Name, item.Name));
                 noError = false;
                 continue;
             }