diff --git a/sw/tools/gen_flight_plan.ml b/sw/tools/gen_flight_plan.ml
index 972704966b..62449a3be6 100644
--- a/sw/tools/gen_flight_plan.ml
+++ b/sw/tools/gen_flight_plan.ml
@@ -800,7 +800,7 @@ let () =
       List.iter
         (fun s ->
         let v = ExtXml.attrib s "name" in
-        lprintf "#define BLOCK_%s %d\n" (Str.global_replace (Str.regexp "[\\. ]") "_" v) !idx; incr idx) blocks;
+        lprintf "#define BLOCK_%s %d\n" (Str.global_replace (Str.regexp "[^A-Za-z0-9]") "_" v) !idx; incr idx) blocks;
         lprintf "\n";
 
       let index_of_waypoints =
diff --git a/sw/tools/gen_settings.ml b/sw/tools/gen_settings.ml
index 087d477f22..2413805309 100644
--- a/sw/tools/gen_settings.ml
+++ b/sw/tools/gen_settings.ml
@@ -74,7 +74,7 @@ let print_dl_settings = fun settings ->
   List.iter
     (fun s ->
       let v = ExtXml.attrib s "var" in
-      lprintf "#define SETTINGS_%s %d\n" (Str.global_replace (Str.regexp "\\.") "_" v) !idx; incr idx)
+      lprintf "#define SETTINGS_%s %d\n" (Str.global_replace (Str.regexp "[^A-Za-z0-9]") "_" v) !idx; incr idx)
     settings;
   lprintf "\n";