diff --git a/CMakeLists.txt b/CMakeLists.txt
index 808dedda2..f6382ed97 100755
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -343,7 +343,15 @@ function(NGL_ADD_SUBDIR_GUARDED subdir)
     # also compare basenames so MIGRATE_MODULE=Lts/DDS matches subdir 'DDS' when called from Lts
     get_filename_component(_mig_base "${_mig}" NAME)
     get_filename_component(_sub_base "${_sub}" NAME)
-    if(_mig MATCHES "^${_sub}(/|$)" OR _sub MATCHES "^${_mig}(/|$)" OR _mig_base STREQUAL _sub OR _sub_base STREQUAL _mig)
+    # If MIGRATE_MODULE either starts with the subdir, equals it, contains it as a path component,
+    # or the basename matches, include the subdir. This makes nested paths like
+    # 'Lts/Proxies/TrainingAreaBase' include both 'Lts' and its child 'Proxies'.
+    if(_mig MATCHES "^${_sub}(/|$)" \
+       OR _sub MATCHES "^${_mig}(/|$)" \
+       OR _mig MATCHES ".*/${_sub}(/|$)" \
+       OR _sub MATCHES ".*/${_mig}(/|$)" \
+       OR _mig_base STREQUAL _sub \
+       OR _sub_base STREQUAL _mig)
       message(STATUS "Including subdir ${subdir} because MIGRATE_MODULE=${MIGRATE_MODULE}")
       add_subdirectory(${subdir})
     else()