diff --git a/CMakeLists.txt b/CMakeLists.txt
index af7400c9f..f7e2ed08b 100644
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -238,6 +238,20 @@ list(APPEND libs ${thirdparty_lib})
 
 add_subdirectory(library)
 
+#
+# The C files in tests/src directory contain test code shared among test suites
+# and programs. This shared test code is compiled and linked to test suites and
+# programs objects as a set of compiled objects. The compiled objects are NOT
+# built into a library that the test suite and program objects would link
+# against as they link against the mbedcrypto, mbedx509 and mbedtls libraries.
+# The reason is that such library is expected to have mutual dependencies with
+# the aforementioned libraries and that there is as of today no portable way of
+# handling such dependencies (only toolchain specific solutions).
+#
+# Thus the below definition of the `mbedtls_test` CMake library of objects
+# target. This library of objects is used by tests and programs CMake files
+# to define the test executables.
+#
 if(ENABLE_TESTING OR ENABLE_PROGRAMS)
     file(GLOB MBEDTLS_TEST_FILES ${CMAKE_CURRENT_SOURCE_DIR}/tests/src/*.c)
     add_library(mbedtls_test OBJECT ${MBEDTLS_TEST_FILES})