diff --git a/script/api_protobuf/api_protobuf.py b/script/api_protobuf/api_protobuf.py
index 81653c3302..05567629b2 100755
--- a/script/api_protobuf/api_protobuf.py
+++ b/script/api_protobuf/api_protobuf.py
@@ -1750,13 +1750,16 @@ def build_message_type(
 
         # Add estimated size constant
         estimated_size = calculate_message_estimated_size(desc)
-        # Validate that estimated_size fits in uint8_t
-        if estimated_size > 255:
-            raise ValueError(
-                f"Estimated size {estimated_size} for {desc.name} exceeds uint8_t maximum (255)"
-            )
+        # Use a type appropriate for estimated_size
+        estimated_size_type = (
+            "uint8_t"
+            if estimated_size <= 255
+            else "uint16_t"
+            if estimated_size <= 65535
+            else "size_t"
+        )
         public_content.append(
-            f"static constexpr uint8_t ESTIMATED_SIZE = {estimated_size};"
+            f"static constexpr {estimated_size_type} ESTIMATED_SIZE = {estimated_size};"
         )
 
         # Add message_name method inline in header