diff --git a/INSTALL b/INSTALL
index d1d5ff7c..3be4d131 100644
--- a/INSTALL
+++ b/INSTALL
@@ -60,8 +60,11 @@ Unit Tests
 ----------
 
 If you want to run the test suite to make sure TagLib works properly on your
-system, you need to have cppunit installed. The test suite has a custom target
-in the build system, so you can run the tests using make:
+system, you need to have cppunit installed. To build the tests, include
+the option -DBUILD_TESTS=on when running cmake.
+
+The test suite has a custom target in the build system, so you can run
+the tests using make:
 
   make check