diff --git a/cyassl/ctaocrypt/tfm.h b/cyassl/ctaocrypt/tfm.h
index d6653a606..e1b16e2d3 100644
--- a/cyassl/ctaocrypt/tfm.h
+++ b/cyassl/ctaocrypt/tfm.h
@@ -663,7 +663,7 @@ void mp_rshb(mp_int *a, int x);
 #ifdef HAVE_ECC
     int mp_read_radix(mp_int* a, const char* str, int radix);
     int mp_set(fp_int *a, fp_digit b);
-    int mp_sqr(fp_int *A, fp_int *B);
+    int mp_sqr(fp_int *a, fp_int *b);
     int mp_montgomery_reduce(fp_int *a, fp_int *m, fp_digit mp);
     int mp_montgomery_setup(fp_int *a, fp_digit *rho);
     int mp_div_2(fp_int * a, fp_int * b);