diff --git a/wolfcrypt/src/sp_int.c b/wolfcrypt/src/sp_int.c
index 1acda20a3..18d1615a6 100644
--- a/wolfcrypt/src/sp_int.c
+++ b/wolfcrypt/src/sp_int.c
@@ -179,6 +179,7 @@ int sp_read_unsigned_bin(sp_int* a, const byte* in, word32 inSz)
 
     for (j++; j < a->size; j++)
         a->dp[j] = 0;
+    sp_clamp(a);
 
     return MP_OKAY;
 }
@@ -234,6 +235,7 @@ int sp_read_radix(sp_int* a, const char* in, int radix)
         for (k++; k < a->size; k++)
             a->dp[k] = 0;
     }
+    sp_clamp(a);
 
     return err;
 }
@@ -485,6 +487,7 @@ int sp_sub_d(sp_int* a, sp_int_digit d, sp_int* r)
     }
     for (++i; i < a->used; i++)
         r->dp[i] = a->dp[i];
+    sp_clamp(r);
 
     return MP_OKAY;
 }
@@ -665,14 +668,18 @@ static int sp_div(sp_int* a, sp_int* d, sp_int* r, sp_int* rem)
 
     ret = sp_cmp(a, d);
     if (ret == MP_LT) {
-        sp_copy(a, rem);
+        if (rem != NULL) {
+            sp_copy(a, rem);
+        }
         if (r != NULL) {
             sp_set(r, 0);
         }
         done = 1;
     }
     else if (ret == MP_EQ) {
-        sp_set(rem, 0);
+        if (rem != NULL) {
+            sp_set(rem, 0);
+        }
         if (r != NULL) {
             sp_set(r, 1);
         }
@@ -680,7 +687,9 @@ static int sp_div(sp_int* a, sp_int* d, sp_int* r, sp_int* rem)
     }
     else if (sp_count_bits(a) == sp_count_bits(d)) {
         /* a is greater than d but same bit length */
-        sp_sub(a, d, rem);
+        if (rem != NULL) {
+            sp_sub(a, d, rem);
+        }
         if (r != NULL) {
             sp_set(r, 1);
         }
@@ -718,6 +727,7 @@ static int sp_div(sp_int* a, sp_int* d, sp_int* r, sp_int* rem)
 
         tr->used = sa->used - d->used;
         sp_clear(tr);
+        tr->used = sa->used - d->used;
         dt = d->dp[d->used-1];
         for (i = sa->used - 1; i >= d->used; i--) {
             w = ((sp_int_word)sa->dp[i] << SP_WORD_SIZE) | sa->dp[i-1];
@@ -835,6 +845,7 @@ int sp_lshd(sp_int* a, int s)
     XMEMMOVE(a->dp + s, a->dp, a->used * sizeof(sp_int_digit));
     a->used += s;
     XMEMSET(a->dp, 0, s * sizeof(sp_int_digit));
+    sp_clamp(a);
 
     return MP_OKAY;
 }
@@ -1303,8 +1314,9 @@ int sp_invmod(sp_int* a, sp_int* m, sp_int* r)
     sp_int u[1], v[1], t[1], b[1], c[1];
 #endif
 
-    if (sp_iszero(a) || sp_iszero(m))
+    if (sp_iszero(a) || sp_iszero(m)) {
         err = MP_VAL;
+    }
     else if (sp_iseven(m)) {
         /* a^-1 mod m = m + (1 - m*(m^-1 % a)) / a
          *            = m - (m*(m^-1 % a) - 1) / a