diff --git a/dev-libs/libbulletml/libbulletml-0.0.6.ebuild b/dev-libs/libbulletml/libbulletml-0.0.6.ebuild
index 8a90adf323960..62b2ec3e1b7d8 100644
--- a/dev-libs/libbulletml/libbulletml-0.0.6.ebuild
+++ b/dev-libs/libbulletml/libbulletml-0.0.6.ebuild
@@ -22,6 +22,9 @@ src_prepare() {
 	epatch "${FILESDIR}"/${P}-gcc43.patch \
 		"${FILESDIR}"/${P}-gcc46.patch
 	rm -r boost || die
+
+	# don't override the system-wide flags
+	sed -i -e '/^CFLAGS =/d;/^CXXFLAGS =/d' Makefile ygg/Makefile || die
 }
 
 src_compile() {