diff --git a/ChangeLog.d/cmake_add_subdirectory_support.txt b/ChangeLog.d/cmake_add_subdirectory_support.txt
new file mode 100644
index 000000000..afcc4b6c4
--- /dev/null
+++ b/ChangeLog.d/cmake_add_subdirectory_support.txt
@@ -0,0 +1,4 @@
+Changes
+   * Add aliases for libraries so that the normal MbedTLS::* targets
+     work when MbedTLS is built as a subdirectory.  Allows use of
+     CMake's FetchContent, as requested in #5688.
diff --git a/library/CMakeLists.txt b/library/CMakeLists.txt
index 6bb2ad38c..c01dbc66f 100644
--- a/library/CMakeLists.txt
+++ b/library/CMakeLists.txt
@@ -279,6 +279,7 @@ if(USE_SHARED_MBEDTLS_LIBRARY)
 endif(USE_SHARED_MBEDTLS_LIBRARY)
 
 foreach(target IN LISTS target_libraries)
+    add_library(MbedTLS::${target} ALIAS ${target})  # add_subdirectory support
     # Include public header files from /include and other directories
     # declared by /3rdparty/**/CMakeLists.txt. Include private header files
     # from /library and others declared by /3rdparty/**/CMakeLists.txt.