diff --git a/techlibs/common/mul2dsp.v b/techlibs/common/mul2dsp.v
index 953fc28d1..3ca69b7b1 100644
--- a/techlibs/common/mul2dsp.v
+++ b/techlibs/common/mul2dsp.v
@@ -61,6 +61,8 @@ module _80_mul (A, B, Y);
 	input [B_WIDTH-1:0] B;
 	output [Y_WIDTH-1:0] Y;
 
+	parameter _TECHMAP_CELLTYPE_ = "";
+
 	generate
 	if (0) begin end
 `ifdef DSP_A_MINWIDTH
@@ -75,8 +77,10 @@ module _80_mul (A, B, Y);
 	else if (Y_WIDTH < `DSP_Y_MINWIDTH)
 		wire _TECHMAP_FAIL_ = 1;
 `endif
+	else if (_TECHMAP_CELLTYPE_ == "$mul" && A_SIGNED != B_SIGNED)
+		wire _TECHMAP_FAIL_ = 1;
 `ifdef DSP_SIGNEDONLY
-	else if (!A_SIGNED)
+	else if (_TECHMAP_CELLTYPE_ == "$mul" && !A_SIGNED)
 		\$mul #(
 			.A_SIGNED(1),
 			.B_SIGNED(1),
@@ -89,7 +93,7 @@ module _80_mul (A, B, Y);
 			.Y(Y)
 		);
 `endif
-	else if (A_WIDTH < B_WIDTH)
+	else if (_TECHMAP_CELLTYPE_ == "$mul" && A_WIDTH < B_WIDTH)
 		\$mul #(
 			.A_SIGNED(B_SIGNED),
 			.B_SIGNED(A_SIGNED),