diff --git a/modules/modperl/CMakeLists.txt b/modules/modperl/CMakeLists.txt
index 58ee9016..650b0da9 100644
--- a/modules/modperl/CMakeLists.txt
+++ b/modules/modperl/CMakeLists.txt
@@ -14,6 +14,9 @@
 # limitations under the License.
 #
 
+# TODO: consider switching to swig_add_library() after bumping CMake
+# requirements to 3.8, when that command started using IMPLICIT_DEPENDS
+
 set(modinclude_modperl PUBLIC ${PERL_INCLUDE_DIRS}
 	"${CMAKE_CURRENT_BINARY_DIR}/.." PARENT_SCOPE)
 set(modcompile_modperl PUBLIC "${PERL_CFLAGS}" PARENT_SCOPE)
diff --git a/modules/modpython/CMakeLists.txt b/modules/modpython/CMakeLists.txt
index 0ba7a6c8..261897e9 100644
--- a/modules/modpython/CMakeLists.txt
+++ b/modules/modpython/CMakeLists.txt
@@ -14,6 +14,9 @@
 # limitations under the License.
 #
 
+# TODO: consider switching to swig_add_library() after bumping CMake
+# requirements to 3.8, when that command started using IMPLICIT_DEPENDS
+
 set(modinclude_modpython PUBLIC ${PYTHON_INCLUDE_DIRS}
 	"${CMAKE_CURRENT_BINARY_DIR}/.." PARENT_SCOPE)
 set(modlink_modpython PUBLIC ${PYTHON_LIBRARIES} PARENT_SCOPE)