diff --git a/rewind.c b/rewind.c
index 8dbcce41d9..31d35ddd5c 100644
--- a/rewind.c
+++ b/rewind.c
@@ -95,7 +95,7 @@ size_t state_manager_raw_maxsize(size_t uncomp)
    /* bytes covered by a compressed block */
    const int maxcblkcover = UINT16_MAX * sizeof(uint16_t);
    /* uncompressed size, rounded to 16 bits */
-   size_t uncomp16        = (uncomp + sizeof(uint16_t) - 1) & ~sizeof(uint16_t);
+   size_t uncomp16        = (uncomp + sizeof(uint16_t) - 1) & -sizeof(uint16_t);
    /* number of blocks */
    size_t maxcblks        = (uncomp + maxcblkcover - 1) / maxcblkcover;
    return uncomp16 + maxcblks * sizeof(uint16_t) * 2 /* two u16 overhead per block */ + sizeof(uint16_t) *
@@ -104,7 +104,7 @@ size_t state_manager_raw_maxsize(size_t uncomp)
 
 void *state_manager_raw_alloc(size_t len, uint16_t uniq)
 {
-   size_t  len16 = (len + sizeof(uint16_t) - 1) & ~sizeof(uint16_t);
+   size_t  len16 = (len + sizeof(uint16_t) - 1) & -sizeof(uint16_t);
 
    uint16_t *ret = (uint16_t*)calloc(len16 + sizeof(uint16_t) * 4 + 16, 1);