diff --git a/chapter05/gcc-exp.xml b/chapter05/gcc-exp.xml
index 74c3a38ec..e5b1e93fe 100644
--- a/chapter05/gcc-exp.xml
+++ b/chapter05/gcc-exp.xml
@@ -5,6 +5,11 @@
 This patch fixes a bug in gcc's linker concerning non-exported (weak) 
 symbols, which was brought to the surface by the new glibc.</para>
 
+<para><userinput>--prefix=usr:</userinput> This is NOT a typo.  GCC hard
+codes some paths while compiling and so we need to pass /usr as the
+prefix during ./configure.  We pass the real install prefix during the
+make install command later.</para>
+
 <para><userinput>--enable-languages=c,c++:</userinput> This only builds the C
 and C++ compilers and not the other available compilers as they are, on
 the average, not often used. If those other compilers are needed,