diff --git a/test_regress/t/t_foreach.pl b/test_regress/t/t_foreach.pl
index 60e20ab59..6b3172aee 100755
--- a/test_regress/t/t_foreach.pl
+++ b/test_regress/t/t_foreach.pl
@@ -15,5 +15,14 @@ execute (
     check_finished=>1,
     );
 
+# We expect all loops should be unrolled by verilator,
+# none of the loop variables should exist in the output:
+file_grep_not ("$Self->{obj_dir}/$Self->{VM_PREFIX}.cpp", qr/index_/);
+
+# Further, we expect that all logic within the loop should
+# have been evaluated inside the compiler. So there should be
+# no references to 'sum' in the .cpp.
+file_grep_not ("$Self->{obj_dir}/$Self->{VM_PREFIX}.cpp", qr/sum/);
+
 ok(1);
 1;
diff --git a/test_regress/t/t_foreach.v b/test_regress/t/t_foreach.v
index 4c9f4c649..e6dcc5cfd 100644
--- a/test_regress/t/t_foreach.v
+++ b/test_regress/t/t_foreach.v
@@ -21,64 +21,68 @@ module t (/*AUTOARG*/);
 
    initial begin
       sum = 0;
-      foreach (depth1_array[index]) begin
-         sum = crc(sum, index, 0, 0, 0);
+      // We use 'index_' as the prefix for all loop vars,
+      // this allows t_foreach.pl to confirm that all loops
+      // have been unrolled and flattened away and no loop vars
+      // remain in the generated .cpp
+      foreach (depth1_array[index_a]) begin
+         sum = crc(sum, index_a, 0, 0, 0);
 
          // Ensure the index never goes out of bounds.
          // We used to get this wrong for an array of depth 1.
-         assert (index != -1);
-         assert (index != 1);
+         assert (index_a != -1);
+         assert (index_a != 1);
       end
       `checkh(sum, 64'h0);
 
       sum = 0;
-      foreach (array[a]) begin
-	 sum = crc(sum, a, 0, 0, 0);
+      foreach (array[index_a]) begin
+         sum = crc(sum, index_a, 0, 0, 0);
       end
       `checkh(sum, 64'h000000c000000000);
 
       sum = 0;
-      foreach (array[a,b]) begin
-	 sum = crc(sum, a, b, 0, 0);
+      foreach (array[index_a,index_b]) begin
+         sum = crc(sum, index_a, index_b, 0, 0);
       end
       `checkh(sum, 64'h000003601e000000);
 
       sum = 0;
-      foreach (array[a,b,c]) begin
-	 sum = crc(sum, a, b, c, 0);
+      foreach (array[index_a,index_b,index_c]) begin
+         sum = crc(sum, index_a, index_b, index_c, 0);
       end
       `checkh(sum, 64'h00003123fc101000);
 
       sum = 0;
-      foreach (array[a,b,c,d]) begin
-	 sum = crc(sum, a, b, c, d);
+      foreach (array[index_a,index_b,index_c,index_d]) begin
+         sum = crc(sum, index_a, index_b, index_c, index_d);
       end
       `checkh(sum, 64'h0030128ab2a8e557);
 
       //
 
       sum = 0;
-      foreach (larray[a]) begin
-	 sum = crc(sum, a, 0, 0, 0);
+      foreach (larray[index_a]) begin
+         sum = crc(sum, index_a, 0, 0, 0);
       end
       `checkh(sum, 64'h0000009000000000);
 
       sum = 0;
-      foreach (larray[a,b]) begin
-	 sum = crc(sum, a, b, 0, 0);
-	 sum = sum + {4'b0,a[7:0], 4'h0,b[7:0]};
+      foreach (larray[index_a,index_b]) begin
+         sum = crc(sum, index_a, index_b, 0, 0);
+         sum = sum + {4'b0,index_a[7:0], 4'h0,index_b[7:0]};
       end
       `checkh(sum, 64'h000002704b057073);
 
       sum = 0;
-      foreach (larray[a,b,c]) begin
-	 sum = crc(sum, a, b, c, 0);
+      foreach (larray[index_a,index_b,index_c]) begin
+         sum = crc(sum, index_a, index_b, index_c, 0);
       end
       `checkh(sum, 64'h00002136f9000000);
 
       sum = 0;
-      foreach (larray[a,b,c,d]) begin
-	 sum = crc(sum, a, b, c, d);
+      foreach (larray[index_a,index_b,index_c,index_d]) begin
+         sum = crc(sum, index_a, index_b, index_c, index_d);
       end
       `checkh(sum, 64'h0020179aa7aa0aaa);