Fix CPPFLAGS setter

diff --git a/configure.ac b/configure.ac
index c407691..68688b7 100644 (file)
--- a/configure.ac
+++ b/configure.ac
@@ -101,7 +101,7 @@ BOOST_LAMBDA
 BOOST_PTR_CONTAINER
 BOOST_STRING_ALGO
 BOOST_TOKENIZER
-CPPFLAGS = "$BOOST_CPPFLAGS $CPPFLAGS"
+CPPFLAGS="$BOOST_CPPFLAGS $CPPFLAGS"
 
 # are covariant methods allowed?
 AC_LINK_IFELSE(