diff --git a/src/roaring.c b/src/roaring.c
index f9be28931..688ae9991 100644
--- a/src/roaring.c
+++ b/src/roaring.c
@@ -2362,7 +2362,8 @@ roaring_bitmap_t *roaring_bitmap_add_offset(const roaring_bitmap_t *bm,
     in_offset = (uint16_t)(offset - container_offset * (1 << 16));
 
     answer = roaring_bitmap_create();
-    roaring_bitmap_set_copy_on_write(answer, is_cow(bm));
+    bool cow = is_cow(bm);
+    roaring_bitmap_set_copy_on_write(answer, cow);
 
     ans_ra = &answer->high_low_container;
 
@@ -2376,11 +2377,9 @@ roaring_bitmap_t *roaring_bitmap_add_offset(const roaring_bitmap_t *bm,
             if (key < 0 || key >= (1 << 16)) {
                 continue;
             }
-
-            ra_append_copy(ans_ra, bm_ra, (uint16_t)i, false);
+            ra_append_copy(ans_ra, bm_ra, (uint16_t)i, cow);
             ans_ra->keys[j++] = (uint16_t)key;
         }
-
         return answer;
     }
 
@@ -2403,7 +2402,6 @@ roaring_bitmap_t *roaring_bitmap_add_offset(const roaring_bitmap_t *bm,
         if (lo_ptr == NULL && hi_ptr == NULL) {
             continue;
         }
-
         c = ra_get_container_at_index(bm_ra, (uint16_t)i, &t);
         c = container_unwrap_shared(c, &t);
 
diff --git a/src/roaring_array.c b/src/roaring_array.c
index 631025b49..f8af3fa94 100644
--- a/src/roaring_array.c
+++ b/src/roaring_array.c
@@ -218,7 +218,7 @@ void ra_append_copy(roaring_array_t *ra, const roaring_array_t *sa,
     extend_array(ra, 1);
     const int32_t pos = ra->size;
 
-    // old contents is junk not needing freeing
+    // old contents is junk that does not need freeing
     ra->keys[pos] = sa->keys[index];
     // the shared container will be in two bitmaps
     if (copy_on_write) {
diff --git a/tests/toplevel_unit.c b/tests/toplevel_unit.c
index 6a6a8ccae..81a34ccff 100644
--- a/tests/toplevel_unit.c
+++ b/tests/toplevel_unit.c
@@ -4719,10 +4719,30 @@ DEFINE_TEST(issue538) {
   roaring_bitmap_free(deserialized);
 }
 
+DEFINE_TEST(issue538b) {
+  int shift = -65536;
+  roaring_bitmap_t *toshift = roaring_bitmap_from_range(131074, 131876, 1);
+  roaring_bitmap_set_copy_on_write(toshift, 1);
+  roaring_bitmap_t *toshift_copy = roaring_bitmap_copy(toshift);
+
+  roaring_bitmap_t *shifted = roaring_bitmap_add_offset(toshift, shift);
+  roaring_bitmap_equals(toshift, toshift_copy);
+
+  roaring_bitmap_t *expected = roaring_bitmap_from_range(131074 + shift, 131876 + shift, 1);
+  roaring_bitmap_set_copy_on_write(expected, 1);
+  assert_true(roaring_bitmap_get_cardinality(toshift) == roaring_bitmap_get_cardinality(expected));
+  assert_true(roaring_bitmap_equals(shifted, expected));
+
+  roaring_bitmap_free(toshift);
+  roaring_bitmap_free(shifted);
+  roaring_bitmap_free(expected);
+}
+
 int main() {
     tellmeall();
 
     const struct CMUnitTest tests[] = {
+        cmocka_unit_test(issue538b),
         cmocka_unit_test(issue538),
         cmocka_unit_test(simple_roaring_bitmap_or_many),
         cmocka_unit_test(robust_deserialization),