diff --git a/IDE/ROWLEY-CROSSWORKS-ARM/user_settings.h b/IDE/ROWLEY-CROSSWORKS-ARM/user_settings.h
index 7947ef34e..f8d751ff0 100644
--- a/IDE/ROWLEY-CROSSWORKS-ARM/user_settings.h
+++ b/IDE/ROWLEY-CROSSWORKS-ARM/user_settings.h
@@ -79,12 +79,13 @@ extern "C" {
     #define ECC_TIMING_RESISTANT
 
     #ifdef USE_FAST_MATH
-        /* Max ECC bits (curve size * 8). ECC256 is (32*8) = 256 */
-        /* Note: ECC521 requires (curve size * 16): (66*16) = 1056 */
+        /* use reduced size math buffers for ecc points */
         #undef  ALT_ECC_SIZE
         #define ALT_ECC_SIZE
+
+        /* optionally override the default max ecc bits */
         #undef  FP_MAX_BITS_ECC
-        #define FP_MAX_BITS_ECC     1056
+        //#define FP_MAX_BITS_ECC     512
 
         /* Enable TFM optimizations for ECC */
         #define TFM_ECC192
diff --git a/wolfssl/wolfcrypt/ecc.h b/wolfssl/wolfcrypt/ecc.h
index f9ca3b41a..a1bc1f61a 100644
--- a/wolfssl/wolfcrypt/ecc.h
+++ b/wolfssl/wolfcrypt/ecc.h
@@ -114,12 +114,12 @@ typedef struct {
 /* determine max bits required for ECC math */
 #ifndef FP_MAX_BITS_ECC
     /* check alignment */
-    #if ((MAX_ECC_BITS & CHAR_BIT) == 0)
+    #if (MAX_ECC_BITS % CHAR_BIT) == 0
         /* max bits is double */
         #define FP_MAX_BITS_ECC     (MAX_ECC_BITS * 2)
     #else
-        /* max bits is rounded up to 8-bit alignment, doubled, plus one digit of fudge */
-        #define FP_MAX_BITS_ECC     ((((MAX_ECC_BITS + CHAR_BIT) & ~CHAR_BIT) * 2) + DIGIT_BIT)
+        /* max bits is doubled, plus one digit of fudge then 8-bit aligned */
+        #define FP_MAX_BITS_ECC     (((MAX_ECC_BITS * 2) + DIGIT_BIT) & ~(CHAR_BIT-1))
     #endif
 #endif