diff --git a/make_rpm_ubuntu26.py b/make_rpm_ubuntu26.py
index 67ebeda..f368134 100755
--- a/make_rpm_ubuntu26.py
+++ b/make_rpm_ubuntu26.py
@@ -109,6 +109,7 @@ def copy_src_dir_to_dest_dir(srcdir, dstdir, perm=None, with_subdirs=True, relea
         'TetraIF',
         'Z/src',
         'Lts/Common',
+        'Lts/Proxies/TrainingAreaBase',  # Required for training_area_telegrams.h used by TetraIF
         'CMakeLists.txt',
         'cmake',
         'tests',
@@ -139,8 +140,14 @@ def copy_src_dir_to_dest_dir(srcdir, dstdir, perm=None, with_subdirs=True, relea
                     # In Z directory, only keep src
                     dirs[:] = [d for d in dirs if d == 'src']
                 elif rel_root == 'Lts':
-                    # In Lts directory, only keep Common
-                    dirs[:] = [d for d in dirs if d == 'Common']
+                    # In Lts directory, only keep Common and Proxies (for TrainingAreaBase)
+                    dirs[:] = [d for d in dirs if d in ('Common', 'Proxies')]
+                elif rel_root == 'Lts/Proxies':
+                    # In Lts/Proxies, only keep TrainingAreaBase
+                    dirs[:] = [d for d in dirs if d == 'TrainingAreaBase']
+                elif rel_root.startswith('Lts/Proxies/TrainingAreaBase'):
+                    # Keep all subdirectories under TrainingAreaBase (DDS code wrapped in conditionals)
+                    pass
                 elif rel_root.startswith('Lts/Common'):
                     # Keep all subdirectories under Lts/Common except LtsUtilsGuiDds (requires DDS)
                     if rel_root == 'Lts/Common/LtsUtils/LtsUtilsGui':