diff --git a/tools/embed/embed.py b/tools/embed/embed.py
index f4b664c..a1f1312 100755
--- a/tools/embed/embed.py
+++ b/tools/embed/embed.py
@@ -237,8 +237,8 @@ namespace {
 
     mid=\
 '''
-    std::unordered_map<std::string,
-                       __embedded_resources::EmbeddedResource>
+    const std::unordered_map<std::string,
+                             __embedded_resources::EmbeddedResource>
     EMBEDDED_RESOURCES =
     {
 ''',