diff --git a/wolfcrypt/src/integer.c b/wolfcrypt/src/integer.c
index 7bfba65b4..81987f96d 100644
--- a/wolfcrypt/src/integer.c
+++ b/wolfcrypt/src/integer.c
@@ -5256,7 +5256,10 @@ int mp_radix_size (mp_int *a, int radix, int *size)
 
     /* special case for binary */
     if (radix == MP_RADIX_BIN) {
-        *size = mp_count_bits (a) + (a->sign == MP_NEG ? 1 : 0) + 1;
+        *size = mp_count_bits(a);
+        if (*size == 0)
+          *size = 1;
+        *size += (a->sign == MP_NEG ? 1 : 0) + 1; /* "-" sign + null term */
         return MP_OKAY;
     }
 
diff --git a/wolfcrypt/src/tfm.c b/wolfcrypt/src/tfm.c
index 6475f669b..aefcdcfe3 100644
--- a/wolfcrypt/src/tfm.c
+++ b/wolfcrypt/src/tfm.c
@@ -5550,8 +5550,11 @@ int mp_radix_size (mp_int *a, int radix, int *size)
 
     /* special case for binary */
     if (radix == 2) {
-        *size = fp_count_bits (a) + (a->sign == FP_NEG ? 1 : 0) + 1;
-        return FP_YES;
+        *size = fp_count_bits(a);
+        if (*size == 0)
+          *size = 1;
+        *size += (a->sign == FP_NEG ? 1 : 0) + 1; /* "-" sign + null term */
+        return FP_OKAY;
     }
 
     /* make sure the radix is in range */