diff --git a/fltk.spec b/fltk.spec
index ed74706..2558a3c 100644
--- a/fltk.spec
+++ b/fltk.spec
@@ -90,15 +90,14 @@ Requires: %{name}-devel
 
 # verbose build output
 sed -i.silent '\,^.SILENT:,d' makeinclude.in
-
 autoconf
 
 
 %build
 
 # using --with-optim, so unset CFLAGS/CXXFLAGS
-export CFLAGS=" "
-export CXXFLAGS=" "
+export CFLAGS=""
+export CXXFLAGS=""
 
 %configure \
   --with-links \