diff --git a/specs/fpga/testbench/router_tb.t27 b/specs/fpga/testbench/router_tb.t27
index ac08a3bf58..84606edd9d 100644
--- a/specs/fpga/testbench/router_tb.t27
+++ b/specs/fpga/testbench/router_tb.t27
@@ -25,8 +25,8 @@ module Router_Testbench {
     var test_failed : u32 = 0;
 
     fn tick() {
-        clk = false;
-        clk = true;
+        // Toggle clock signal for one clock cycle
+        clk = !clk;
     }
 
     fn reset() {
@@ -55,48 +55,54 @@ module Router_Testbench {
         return (nets * 100) / capacity;
     }
 
-    test test_reset_state {
+    test "test_reset_state" {
         reset();
         invariant route_done == false;
         invariant route_valid == false;
     }
 
-    test test_manhattan_distance_zero {
+    test "test_manhattan_distance_zero" {
         var d : u32 = manhattan_distance(0, 0, 0, 0);
         invariant d == 0;
     }
 
-    test test_manhattan_distance_simple {
+    test "test_manhattan_distance_simple" {
         var d : u32 = manhattan_distance(0, 0, 3, 4);
         invariant d == 7;
     }
 
-    test test_manhattan_distance_symmetric {
+    test "test_manhattan_distance_symmetric" {
         var d1 : u32 = manhattan_distance(1, 2, 5, 8);
         var d2 : u32 = manhattan_distance(5, 8, 1, 2);
         invariant d1 == d2;
     }
 
-    test test_wire_length_estimate {
+    test "test_wire_length_estimate" {
         var wl : u32 = estimate_wire_length(16, 10);
         invariant wl > 0;
     }
 
-    test test_congestion_low {
+    test "test_congestion_low" {
         var c : u32 = congestion_factor(10, 100);
         invariant c == 10;
     }
 
-    test test_congestion_full {
+    test "test_congestion_full" {
         var c : u32 = congestion_factor(100, 100);
         invariant c == 100;
     }
 
-    test test_grid_size {
+    test "test_grid_size" {
         invariant GRID_SIZE == 16;
         invariant NUM_LAYERS == 2;
     }
 
+    test "test_tick" {
+        var initial_clk : bool = clk;
+        tick();
+        invariant clk != initial_clk;
+    }
+
     invariant grid_positive : GRID_SIZE > 0;
     invariant layers_positive : NUM_LAYERS > 0;