diff --git a/tests/test-atoms.c b/tests/test-atoms.c
index 6d47904d..bc44cd35 100644
--- a/tests/test-atoms.c
+++ b/tests/test-atoms.c
@@ -131,6 +131,31 @@ void test_heuristic_quality()
       .bytes = {0x01, 0x02, 0x03, 0x04},
       .mask = {0xFF, 0xFF, 0x00, 0xFF}};
 
+  YR_ATOM a90909090 = {
+      .length = 4,
+      .bytes = {0x90, 0x90, 0x90, 0x90},
+      .mask = {0xFF, 0xFF, 0xFF, 0xFF}};
+
+  YR_ATOM a20202020 = {
+      .length = 4,
+      .bytes = {0x20, 0x20, 0x20, 0x20},
+      .mask = {0xFF, 0xFF, 0xFF, 0xFF}};
+
+  YR_ATOM aCCCCCCCC = {
+      .length = 4,
+      .bytes = {0xCC, 0xCC, 0xCC, 0xCC},
+      .mask = {0xFF, 0xFF, 0xFF, 0xFF}};
+
+  YR_ATOM aFFFFFFFF = {
+      .length = 4,
+      .bytes = {0xFF, 0xFF, 0xFF, 0xFF},
+      .mask = {0xFF, 0xFF, 0xFF, 0xFF}};
+
+  YR_ATOM a01010101 = {
+      .length = 4,
+      .bytes = {0x01, 0x01, 0x01, 0x01},
+      .mask = {0xFF, 0xFF, 0xFF, 0xFF}};
+
   c.get_atom_quality = yr_atoms_heuristic_quality;
 
   int q00000000 = yr_atoms_heuristic_quality(&c, &a00000000);
@@ -146,6 +171,11 @@ void test_heuristic_quality()
   int q000102 = yr_atoms_heuristic_quality(&c, &a000102);
   int q01020000 = yr_atoms_heuristic_quality(&c, &a01020000);
   int q0102XX04 = yr_atoms_heuristic_quality(&c, &a0102XX04);
+  int q01010101 = yr_atoms_heuristic_quality(&c, &a01010101);
+  int q20202020 = yr_atoms_heuristic_quality(&c, &a20202020);
+  int q90909090 = yr_atoms_heuristic_quality(&c, &a90909090);
+  int qCCCCCCCC = yr_atoms_heuristic_quality(&c, &aCCCCCCCC);
+  int qFFFFFFFF = yr_atoms_heuristic_quality(&c, &aFFFFFFFF);
 
   a010203.mask[1] = 0x00;
 
@@ -185,6 +215,16 @@ void test_heuristic_quality()
   assert_true_expr(q010X0X < q010203);
   assert_true_expr(q01020000 > q0102XX04);
 
+  // Byte sequences like 90 90 90 90 and CC CC CC CC are using as function
+  // padding by compilers (sequences of NOP and INT 3 instructions respectively)
+  // and therefore are very common. FF FF FF FF and 20 20 20 20 (spaces) are
+  // also very common sequences. All these common sequences are penalized and
+  // have lower qualities than 01 01 01 01.
+  assert_true_expr(q90909090 < q01010101);
+  assert_true_expr(q20202020 < q01010101);
+  assert_true_expr(qCCCCCCCC < q01010101);
+  assert_true_expr(qFFFFFFFF < q01010101);
+
   assert_true_expr(q01020304 == YR_MAX_ATOM_QUALITY);
 }