diff --git a/firefox-mozconfig b/firefox-mozconfig
index 3ff8c29..09cedb5 100755
--- a/firefox-mozconfig
+++ b/firefox-mozconfig
@@ -10,9 +10,7 @@ ac_add_options --with-system-zlib
 ac_add_options --with-pthreads
 ac_add_options --disable-tests
 ac_add_options --disable-debug
-ac_add_options --enable-optimize="$MOZ_OPT_FLAGS"
-#ac_add_options --enable-debug
-#ac_add_options --disable-optimize
+ac_add_options --enable-optimize
 ac_add_options --disable-installer
 ac_add_options --enable-xinerama
 ac_add_options --enable-default-toolkit=cairo-gtk2
diff --git a/firefox.spec b/firefox.spec
index db23a55..be56c62 100644
--- a/firefox.spec
+++ b/firefox.spec
@@ -145,7 +145,11 @@ cd %{tarballdir}
 
 # Mozilla builds with -Wall with exception of a few warnings which show up
 # everywhere in the code; so, don't override that.
-export MOZ_OPT_FLAGS=$(echo $RPM_OPT_FLAGS | %{__sed} -e 's/-Wall//' | %{__sed} -e 's/-fexceptions/-fno-exceptions/g')
+#
+# Disable C++ exceptions since Mozilla code is not exception-safe
+#
+MOZ_OPT_FLAGS=$(echo $RPM_OPT_FLAGS | \
+                     %{__sed} -e 's/-Wall//' -e 's/-fexceptions/-fno-exceptions/g')
 export CFLAGS=$MOZ_OPT_FLAGS
 export CXXFLAGS=$MOZ_OPT_FLAGS