diff --git a/src/app/rom.cc b/src/app/rom.cc
index 664372f5..5b3bb576 100644
--- a/src/app/rom.cc
+++ b/src/app/rom.cc
@@ -208,11 +208,6 @@ absl::Status Rom::LoadZelda3() {
   constexpr size_t baseROMSize = 1048576;  // 1MB
   constexpr size_t headerSize = 0x200;     // 512 bytes
   if (size_ % baseROMSize == headerSize) {
-    has_header_ = true;
-  }
-
-  // Remove header if present
-  if (has_header_) {
     auto header =
         std::vector<uchar>(rom_data_.begin(), rom_data_.begin() + 0x200);
     rom_data_.erase(rom_data_.begin(), rom_data_.begin() + 0x200);
diff --git a/src/app/rom.h b/src/app/rom.h
index 53f7f550..49d6efc3 100644
--- a/src/app/rom.h
+++ b/src/app/rom.h
@@ -212,7 +212,11 @@ class Rom : public core::ExperimentFlags {
 
   absl::Status ReadWritePreconditions() {
     if (!is_loaded_) {
-      return absl::FailedPreconditionError("ROM not loaded");
+      return absl::FailedPreconditionError("ROM file not loaded");
+    }
+    if (rom_data_.empty() || size_ == 0) {
+      return absl::FailedPreconditionError(
+          "File was loaded, but ROM data was empty.");
     }
     return absl::OkStatus();
   }
@@ -499,7 +503,6 @@ class Rom : public core::ExperimentFlags {
     }
     auto error_message = absl::StrFormat("Invalid write argument type: %s",
                                          typeid(action.value).name());
-    throw std::runtime_error(error_message);
     return absl::InvalidArgumentError(error_message);
   }
 
@@ -522,10 +525,16 @@ class Rom : public core::ExperimentFlags {
   absl::Status LoadGfxGroups();
   absl::Status SaveGroupsToRom();
 
-  long size_ = 0;
+  // ROM file loaded flag
   bool is_loaded_ = false;
-  bool has_header_ = false;
-  std::string title_ = "ROM Not Loaded";
+
+  // Size of the ROM data.
+  unsigned long size_ = 0;
+
+  // Title of the ROM loaded from the header
+  std::string title_ = "ROM not loaded";
+
+  // Filename of the ROM
   std::string filename_ = "";
 
   // Full contiguous rom space