diff --git a/INSTALL b/INSTALL
index 4a850da..82ddfeb 100644
--- a/INSTALL
+++ b/INSTALL
@@ -26,9 +26,8 @@
 -----------------------
 
  Once EFL is built and installed in your desired destination, proceed with
- building the wrapper. If you downloaded a tarball with pre-generated
- C sources you can proceed to use those, or force distutils to use pyx
- sources by setting the environment variable USE_CYTHON to 1.
+ building the wrapper. The setup script can be forced to use purely C
+ sources by setting the environment variable DISABLE_CYTHON to 1.
 
 
  * BUILDING WITH GCC/G++ (Linux, OS X, etc.)
@@ -43,9 +42,9 @@
 
    python setup.py build -c mingw32
 
- * FORCING PYX SOURCES FOR BUILD
+ * FORCING C SOURCES FOR BUILD
 
-   env USE_CYTHON=1 python setup.py build
+   env DISABLE_CYTHON=1 python setup.py build