diff --git a/src/gallium/drivers/r600/evergreen_state.c b/src/gallium/drivers/r600/evergreen_state.c
index af5c0dd71d1..7587fd45bb9 100644
--- a/src/gallium/drivers/r600/evergreen_state.c
+++ b/src/gallium/drivers/r600/evergreen_state.c
@@ -2035,7 +2035,7 @@ static void evergreen_emit_cb_misc_state(struct r600_context *rctx, struct r600_
 	struct r600_cb_misc_state *a = (struct r600_cb_misc_state*)atom;
 	unsigned fb_colormask = a->bound_cbufs_target_mask;
 	unsigned ps_colormask = a->ps_color_export_mask;
-	unsigned rat_colormask = evergreen_construct_rat_mask(rctx, a, a->nr_cbufs);
+	unsigned rat_colormask = evergreen_construct_rat_mask(rctx, a, a->nr_cbufs + (a->dual_src_blend ? 1 : 0));
 	radeon_set_context_reg_seq(cs, R_028238_CB_TARGET_MASK, 2);
 	radeon_emit(cs, (a->blend_colormask & fb_colormask) | rat_colormask); /* R_028238_CB_TARGET_MASK */
 	/* This must match the used export instructions exactly.