diff --git a/configure b/configure
index 841c3d2..a7f460a 100755
--- a/configure
+++ b/configure
@@ -3360,7 +3360,7 @@ elif test "`uname`" == "Darwin" ; then
     curl -sSL "$quantlib" -o quantlib.tar.xz
     tar xf quantlib.tar.xz --strip 1 -C "$quantlibdir"
     rm quantlib.tar.xz
-    pkg_cxxflags="-I${quantlibdir}/include"
+    pkg_cxxflags="-I${quantlibdir}/include -Wno-enum-constexpr-conversion"
     pkg_libs="-L${quantlibdir}/lib -lQuantLib"
 
     # Same as above
diff --git a/configure.ac b/configure.ac
index febef05..8e3a4d5 100644
--- a/configure.ac
+++ b/configure.ac
@@ -100,7 +100,7 @@ elif test "`uname`" == "Darwin" ; then
     curl -sSL "$quantlib" -o quantlib.tar.xz
     tar xf quantlib.tar.xz --strip 1 -C "$quantlibdir"
     rm quantlib.tar.xz
-    pkg_cxxflags="-I${quantlibdir}/include"
+    pkg_cxxflags="-I${quantlibdir}/include -Wno-enum-constexpr-conversion"
     pkg_libs="-L${quantlibdir}/lib -lQuantLib"
 
     # Same as above