diff --git a/wolfcrypt/src/integer.c b/wolfcrypt/src/integer.c
index a5afd8ca1..dff9545a6 100644
--- a/wolfcrypt/src/integer.c
+++ b/wolfcrypt/src/integer.c
@@ -4562,6 +4562,7 @@ static int mp_div_d (mp_int * a, mp_digit b, mp_int * c, mp_digit * d)
      if (w >= b) {
 #ifdef WOLFSSL_LINUXKM
         t = (mp_digit)w;
+	/* Linux kernel macro for in-place 64 bit integer division. */
         do_div(t, b);
 #else
         t = (mp_digit)(w / b);
diff --git a/wolfcrypt/src/tfm.c b/wolfcrypt/src/tfm.c
index 91563ad5b..dfc2f7a6d 100644
--- a/wolfcrypt/src/tfm.c
+++ b/wolfcrypt/src/tfm.c
@@ -754,6 +754,7 @@ int fp_div(fp_int *a, fp_int *b, fp_int *c, fp_int *d)
       tmp = ((fp_word) x->dp[i]) << ((fp_word) DIGIT_BIT);
       tmp |= ((fp_word) x->dp[i - 1]);
 #ifdef WOLFSSL_LINUXKM
+      /* Linux kernel macro for in-place 64 bit integer division. */
       do_div(tmp, (fp_word)y->dp[t]);
 #else
       tmp /= ((fp_word)y->dp[t]);
@@ -4566,6 +4567,7 @@ static int fp_div_d(fp_int *a, fp_digit b, fp_int *c, fp_digit *d)
      if (w >= b) {
 #ifdef WOLFSSL_LINUXKM
         t = (fp_digit)w;
+	/* Linux kernel macro for in-place 64 bit integer division. */
         do_div(t, b);
 #else
         t = (fp_digit)(w / b);