diff --git a/SDL3-CS/Utf8String.cs b/SDL3-CS/Utf8String.cs
index 832b44f..8754bfb 100644
--- a/SDL3-CS/Utf8String.cs
+++ b/SDL3-CS/Utf8String.cs
@@ -24,10 +24,16 @@ namespace SDL
             if (str == null)
                 return new Utf8String(null);
 
-            if (str.EndsWith('\0'))
+            if (str.Length == 0)
+                return new Utf8String("\0"u8);
+
+            if (str[^1] == '\0')
                 return new Utf8String(Encoding.UTF8.GetBytes(str));
 
-            return new Utf8String(Encoding.UTF8.GetBytes(str + '\0'));
+            int len = Encoding.UTF8.GetByteCount(str);
+            byte[] bytes = new byte[len + 1];
+            Encoding.UTF8.GetBytes(str, bytes);
+            return new Utf8String(bytes);
         }
 
         public static implicit operator Utf8String(ReadOnlySpan<byte> raw)
@@ -36,16 +42,14 @@ namespace SDL
                 return new Utf8String(null);
 
             if (raw.Length == 0)
-                return new Utf8String(new ReadOnlySpan<byte>([0]));
+                return new Utf8String("\0"u8);
 
-            if (raw[^1] != 0)
-            {
-                byte[] copy = new byte[raw.Length + 1];
-                raw.CopyTo(copy);
-                raw = copy;
-            }
+            if (raw[^1] == 0)
+                return new Utf8String(raw);
 
-            return new Utf8String(raw);
+            byte[] copy = new byte[raw.Length + 1];
+            raw.CopyTo(copy);
+            return new Utf8String(copy);
         }
 
         internal ref readonly byte GetPinnableReference() => ref Raw.GetPinnableReference();