diff --git a/techlibs/common/mul2dsp.v b/techlibs/common/mul2dsp.v
index 3ca69b7b1..9932e288f 100644
--- a/techlibs/common/mul2dsp.v
+++ b/techlibs/common/mul2dsp.v
@@ -77,10 +77,8 @@ module _80_mul (A, B, Y);
 	else if (Y_WIDTH < `DSP_Y_MINWIDTH)
 		wire _TECHMAP_FAIL_ = 1;
 `endif
-	else if (_TECHMAP_CELLTYPE_ == "$mul" && A_SIGNED != B_SIGNED)
-		wire _TECHMAP_FAIL_ = 1;
 `ifdef DSP_SIGNEDONLY
-	else if (_TECHMAP_CELLTYPE_ == "$mul" && !A_SIGNED)
+	else if (_TECHMAP_CELLTYPE_ == "$mul" && !A_SIGNED && !B_SIGNED)
 		\$mul #(
 			.A_SIGNED(1),
 			.B_SIGNED(1),