diff --git a/wolfcrypt/src/sp_int.c b/wolfcrypt/src/sp_int.c
index b8eb2e339..28ca2f33d 100644
--- a/wolfcrypt/src/sp_int.c
+++ b/wolfcrypt/src/sp_int.c
@@ -950,7 +950,7 @@ static int sp_div(sp_int* a, sp_int* d, sp_int* r, sp_int* rem)
         }
         for (i = sa->used - 1; i >= d->used; i--) {
             if (sa->dp[i] == dt) {
-                t = (sp_digit)-1;
+                t = SP_MASK; /* f's */
             }
             else {
                 t = sp_div_word(sa->dp[i], sa->dp[i-1], dt);
diff --git a/wolfssl/wolfcrypt/sp_int.h b/wolfssl/wolfcrypt/sp_int.h
index db8fd4433..9d3e124cb 100644
--- a/wolfssl/wolfcrypt/sp_int.h
+++ b/wolfssl/wolfcrypt/sp_int.h
@@ -85,8 +85,6 @@ This library provides single precision (SP) integer math functions.
     #endif
     typedef uint128_t sp_int_word;
     typedef int128_t sp_int_sword;
-  #else
-    #error Word size not defined
   #endif
 #else
   #if SP_WORD_SIZE == 32
@@ -106,12 +104,16 @@ This library provides single precision (SP) integer math functions.
     #endif
     typedef uint128_t sp_int_word;
     typedef int128_t sp_int_sword;
-  #else
-    #error Word size not defined
   #endif
 #endif
 
-#define SP_MASK    (sp_digit)(-1)
+#if SP_WORD_SIZE == 32
+    #define SP_MASK ((sp_digit)0xffffffff)
+#elif SP_WORD_SIZE == 64
+    #define SP_MASK ((sp_digit)0xffffffffffffffff)
+#else
+    #error Word size not defined
+#endif
 
 
 #if defined(WOLFSSL_HAVE_SP_ECC) && defined(WOLFSSL_SP_NONBLOCK)