diff --git a/test-tool/test_compareandwrite_miscompare.c b/test-tool/test_compareandwrite_miscompare.c
index 5f0dbac..3fb6374 100644
--- a/test-tool/test_compareandwrite_miscompare.c
+++ b/test-tool/test_compareandwrite_miscompare.c
@@ -41,10 +41,10 @@ test_compareandwrite_miscompare(void)
                 maxbl = inq_bl->max_cmp;
         } else {
                 /* Assume we are not limited */
-                maxbl = 256;
+                maxbl = 255;
         }
 
-        n = 256;
+        n = 255;
         if (n + 0U > num_blocks)
                 n = num_blocks;
 
diff --git a/test-tool/test_compareandwrite_simple.c b/test-tool/test_compareandwrite_simple.c
index 842cf3b..4fe5594 100644
--- a/test-tool/test_compareandwrite_simple.c
+++ b/test-tool/test_compareandwrite_simple.c
@@ -41,10 +41,10 @@ test_compareandwrite_simple(void)
                 maxbl = inq_bl->max_cmp;
         } else {
                 /* Assume we are not limited */
-                maxbl = 256;
+                maxbl = 255;
         }
 
-        n = 256;
+        n = 255;
         if (n + 0U > num_blocks)
                 n = num_blocks;
         if (maxbl + 0U > num_blocks)
diff --git a/test-tool/test_multipathio_compareandwrite.c b/test-tool/test_multipathio_compareandwrite.c
index 96c47ce..750884e 100644
--- a/test-tool/test_multipathio_compareandwrite.c
+++ b/test-tool/test_multipathio_compareandwrite.c
@@ -44,14 +44,14 @@ test_multipathio_compareandwrite(void)
                 maxbl = inq_bl->max_cmp;
         } else {
                 /* Assume we are not limited */
-                maxbl = 256;
+                maxbl = 255;
         }
         if (maxbl < io_bl) {
                 CU_PASS("[SKIPPED] MAXIMUM_COMPARE_AND_WRITE_LENGTH too small");
                 return;
         }
 
-        n = 256;
+        n = 255;
         if (n + 0U > num_blocks)
                 n = num_blocks;