diff --git a/README.md b/README.md
index a19deea..60d6b94 100644
--- a/README.md
+++ b/README.md
@@ -30,11 +30,28 @@ You can then build and install the static `libopenlibm.a` archive and the header
 % make USEGCC=1 TOOLPREFIX=sh-elf- libdir="$PREFIX" includedir="$PREFIX/include" install-static install-headers
 ```
 
-## Using in a program
+## Using in a Makefile-based add-in
 
-Simply link with `-lopenlibm` as you would do with `-lm`.
+Link with `-lopenlibm` as you would do with `-lm`. Since OpenLibm headers
+reference themselves by file name (`#include <openlibm_complex.h>`) even though
+they are installed in a subfolder, you need a `-I` flag:
+
+```
+CFLAGS += -I $(shell sh-elf-gcc -print-file-name=include/openlibm)
+LDFLAGS += -lopenlibm
+```
+
+## Using in a CMake-based add-in
+
+When using CMake with the fxSDK, add the include folder and library like this.
+
+```
+target_include_directories(<TARGET> PRIVATE "${FXSDK_COMPILER_INSTALL}/include/openlibm")
+target_link_libraries(<TARGET> -lopenlibm)
+```
 
 ## README and Licensing
 
-See the original README file in README-OpenLibm.md. OpenLibm contains code
-covered by various licenses, see LICENSE.md.
+See the original README file in [README-OpenLibm.md](README-OpenLibm.md).
+OpenLibm contains code covered by various licenses, see
+[LICENSE.md](LICENSE.md).