diff --git a/techlibs/ecp5/cells_bb.v b/techlibs/ecp5/cells_bb.v
index 0a5046db2..ae124e7a3 100644
--- a/techlibs/ecp5/cells_bb.v
+++ b/techlibs/ecp5/cells_bb.v
@@ -333,6 +333,13 @@ module ECLKSYNCB(
 );
 endmodule
 
+(* blackbox *)
+module ECLKBRIDGECS(
+	input CLK0, CLK1, SEL,
+	output ECSOUT
+);
+endmodule
+
 (* blackbox *)
 module DCCA(
 	input CLKI, CE,