diff --git a/tests/ice40/latches.ys b/tests/ice40/latches.ys
index fe0d1f70e..f3562559e 100644
--- a/tests/ice40/latches.ys
+++ b/tests/ice40/latches.ys
@@ -1,6 +1,15 @@
 read_verilog latches.v
+design -save read
+
+proc
+async2sync # converts latches to a 'sync' variant clocked by a 'super'-clock
+flatten
+synth_ice40
+equiv_opt -assert -map +/ice40/cells_sim.v synth_ice40 # equivalency check
+design -load postopt # load the post-opt design (otherwise equiv_opt loads the pre-opt design)
+
+design -load read
 synth_ice40
 cd top
 select -assert-count 4 t:SB_LUT4
 select -assert-none t:SB_LUT4 %% t:* %D
-write_verilog latches_synth.v
diff --git a/tests/ice40/latches_tb.v b/tests/ice40/latches_tb.v
deleted file mode 100644
index b0585264b..000000000
--- a/tests/ice40/latches_tb.v
+++ /dev/null
@@ -1,57 +0,0 @@
-module testbench;
-    reg clk;
-
-    initial begin
-        // $dumpfile("testbench.vcd");
-        // $dumpvars(0, testbench);
-
-        #5 clk = 0;
-        repeat (10000) begin
-            #5 clk = 1;
-            #5 clk = 0;
-        end
-    end
-
-
-    reg [2:0] dinA = 0;
-    wire doutB,doutB1,doutB2;
-	reg lat,latn,latsr = 0;
-
-    top uut (
-        .clk (clk ),
-        .a (dinA[0] ),
-        .pre (dinA[1] ),
-        .clr (dinA[2] ),
-        .b (doutB ),
-        .b1 (doutB1 ),
-        .b2 (doutB2 )
-    );
-
-    always @(posedge clk) begin
-    #3;
-    dinA <= dinA + 1;
-    end
-
-    	always @*
-		if ( clk )
-			lat <= dinA[0];
-
-
-    	always @*
-		if ( !clk )
-			latn <= dinA[0];
-
-
-		always @*
-		if ( dinA[2] )
-			latsr <= 1'b0;
-		else if ( dinA[1] )
-			latsr <= 1'b1;
-		else if ( clk )
-			latsr <= dinA[0];
-
-	assert_dff lat_test(.clk(clk), .test(doutB), .pat(lat));
-    assert_dff latn_test(.clk(clk), .test(doutB1), .pat(latn));
-    assert_dff latsr_test(.clk(clk), .test(doutB2), .pat(latsr));
-
-endmodule