diff --git a/panda/src/express/error_utils.cxx b/panda/src/express/error_utils.cxx
index 5306a98451..db27a89240 100644
--- a/panda/src/express/error_utils.cxx
+++ b/panda/src/express/error_utils.cxx
@@ -87,6 +87,8 @@ error_to_text(int err) {
       return "EU_error_abort";
     case EU_error_file_empty:
       return "EU_error_file_empty";
+    case EU_error_file_invalid:
+      return "EU_error_file_invalid";
     case EU_error_network_dead:
       return "EU_error_network_dead";
     case EU_error_network_unreachable:
@@ -127,6 +129,8 @@ error_to_text(int err) {
       return "EU_error_write_disk_sector_not_found";
     case EU_error_write_disk_fault:
       return "EU_error_write_disk_fault";
+    case EU_error_write_file_rename:
+      return "EU_error_write_file_rename";
     case EU_error_http_server_timeout:
       return "EU_error_http_server_timeout";
     case EU_error_http_gateway_timeout:
diff --git a/panda/src/express/error_utils.h b/panda/src/express/error_utils.h
index e789d89e54..b8a0d5a911 100644
--- a/panda/src/express/error_utils.h
+++ b/panda/src/express/error_utils.h
@@ -22,6 +22,7 @@ enum ErrorUtilCode {
   // General errors
   EU_error_abort = -1,
   EU_error_file_empty = -2,
+  EU_error_file_invalid = -3,
 
   // General network errors
   EU_error_network_dead = -30,
@@ -50,6 +51,7 @@ enum ErrorUtilCode {
   EU_error_write_disk_not_found = -64,
   EU_error_write_disk_sector_not_found = -65,
   EU_error_write_disk_fault = -66,
+  EU_error_write_file_rename = -67,
 
   // HTTP errors
   EU_error_http_server_timeout = -70,
diff --git a/panda/src/express/patchfile.cxx b/panda/src/express/patchfile.cxx
index 492c15ac0d..c85c344001 100644
--- a/panda/src/express/patchfile.cxx
+++ b/panda/src/express/patchfile.cxx
@@ -211,8 +211,7 @@ initiate(Filename &patch_file, Filename &file) {
   if (magic_number != _magic_number) {
     express_cat.error()
       << "Patchfile::apply() - invalid patch file: " << _patch_file << endl;
-    //return PF_error_invalidpatchfile;
-    return EU_error_abort;
+    return EU_error_file_invalid;
   }
 
   // get the length of the patched result file
@@ -230,8 +229,7 @@ initiate(Filename &patch_file, Filename &file) {
     express_cat.error()
       << "Patchfile::apply() - patch intended for file: " << name
       << ", not file: " << file << endl;
-    //return PF_error_wrongpatchfile;
-    return EU_error_abort;
+    return EU_error_file_invalid;
   }
 
   express_cat.debug()
@@ -348,8 +346,7 @@ run(void) {
         express_cat.error()
           << "Patchfile::apply() failed to rename temp file to: " << _orig_file
           << endl;
-        //return PF_error_renamingtempfile;
-        return EU_error_abort;
+        return EU_error_write_file_rename;
       }
 
       return EU_success;