diff --git a/glamor/glamor.c b/glamor/glamor.c
index a11e2212d8ff2bf3f2871fc93102f4981238fda6..ac8481849ea06d33f241534a3fc2abf0b3ec2f7a 100644
--- a/glamor/glamor.c
+++ b/glamor/glamor.c
@@ -798,7 +798,8 @@ glamor_init(ScreenPtr screen, unsigned int flags)
         epoxy_has_gl_extension("GL_NV_pack_subimage");
     glamor_priv->has_dual_blend =
         glamor_priv->glsl_version >= 130 &&
-        epoxy_has_gl_extension("GL_ARB_blend_func_extended");
+        (epoxy_has_gl_extension("GL_ARB_blend_func_extended") ||
+         epoxy_has_gl_extension("GL_EXT_blend_func_extended"));
     glamor_priv->has_clear_texture =
         epoxy_gl_version() >= 44 ||
         epoxy_has_gl_extension("GL_ARB_clear_texture");