diff --git a/library/CMakeLists.txt b/library/CMakeLists.txt
index c551ee5..8fd959c 100644
--- a/library/CMakeLists.txt
+++ b/library/CMakeLists.txt
@@ -192,6 +192,11 @@
 endif(USE_SHARED_MBEDTLS_LIBRARY)
 
 foreach(target IN LISTS target_libraries)
+    # 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.
+    # /library needs to be listed explicitly when building .c files outside
+    # of /library (which currently means: under /3rdparty).
     target_include_directories(${target}
         PUBLIC ${MBEDTLS_DIR}/include/
         PUBLIC ${thirdparty_inc_public}
diff --git a/library/Makefile b/library/Makefile
index 801304b..20a5984 100644
--- a/library/Makefile
+++ b/library/Makefile
@@ -5,6 +5,10 @@
 WARNING_CFLAGS ?=  -Wall -Wextra
 LDFLAGS ?=
 
+# Include ../include for public headers and . for private headers.
+# Note that . needs to be included explicitly for the sake of library
+# files that are not in the /library directory (which currently means
+# under /3rdparty).
 LOCAL_CFLAGS = $(WARNING_CFLAGS) -I. -I../include -D_FILE_OFFSET_BITS=64
 LOCAL_LDFLAGS =