Index: sources/configure.ac
===================================================================
--- sources/configure.ac	(revision 63)
+++ sources/configure.ac	(revision 64)
@@ -45,5 +45,5 @@
 # Also set -DNDEBUG when not debugging, this disables assert()s
 AS_IF([test "x$do_debug"  = "xyes"], [CXXFLAGS="-g"],
-      [test "x$do_debug" != "xyes"], [CXXFLAGS="-O2 -DNDEBUG"])
+      [test "x$do_debug" != "xyes"], [CXXFLAGS="-O3 -DNDEBUG"])
 
 case $target_os in