diff --git a/INSTALL.md b/INSTALL.md
index 77cbe6c3e..3b520f78c 100644
--- a/INSTALL.md
+++ b/INSTALL.md
@@ -79,6 +79,7 @@ website (you need to be registered):
 Install the MacOSX10.4.Universal.pkg and run cmake with the following
 parameters:
 
+    -DCMAKE_OSX_ARCHITECTURES:STRING=i386
     -DCMAKE_OSX_DEPLOYMENT_TARGET:STRING=10.4
     -DCMAKE_OSX_SYSROOT:STRING=/SDKs/MacOSX10.4u.sdk