diff --git a/bn_mp_clear.c b/bn_mp_clear.c
index 1f360b278..b8e724cfc 100644
--- a/bn_mp_clear.c
+++ b/bn_mp_clear.c
@@ -25,7 +25,7 @@ void mp_clear(mp_int *a)
       }
 
       /* free ram */
-      XFREE(a->dp);
+      XFREE(a->dp, sizeof (mp_digit) * (size_t)a->alloc);
 
       /* reset members to make debugging easier */
       a->dp    = NULL;
diff --git a/bn_mp_fwrite.c b/bn_mp_fwrite.c
index 3bcb4452c..85a942fdd 100644
--- a/bn_mp_fwrite.c
+++ b/bn_mp_fwrite.c
@@ -28,18 +28,18 @@ int mp_fwrite(const mp_int *a, int radix, FILE *stream)
    }
 
    if ((err = mp_toradix(a, buf, radix)) != MP_OKAY) {
-      XFREE(buf);
+      XFREE(buf, len);
       return err;
    }
 
    for (x = 0; x < len; x++) {
       if (fputc((int)buf[x], stream) == EOF) {
-         XFREE(buf);
+         XFREE(buf, len);
          return MP_VAL;
       }
    }
 
-   XFREE(buf);
+   XFREE(buf, len);
    return MP_OKAY;
 }
 #endif
diff --git a/bn_mp_grow.c b/bn_mp_grow.c
index 139445107..b12019414 100644
--- a/bn_mp_grow.c
+++ b/bn_mp_grow.c
@@ -29,7 +29,9 @@ int mp_grow(mp_int *a, int size)
        * in case the operation failed we don't want
        * to overwrite the dp member of a.
        */
-      tmp = (mp_digit *) XREALLOC(a->dp, (size_t)size * sizeof(mp_digit));
+      tmp = (mp_digit *) XREALLOC(a->dp,
+                                  (size_t)a->alloc * sizeof (mp_digit),
+                                  (size_t)size * sizeof(mp_digit));
       if (tmp == NULL) {
          /* reallocation failed but "a" is still valid [can be freed] */
          return MP_MEM;
diff --git a/bn_mp_prime_random_ex.c b/bn_mp_prime_random_ex.c
index fdd5140c2..0ca29ecbf 100644
--- a/bn_mp_prime_random_ex.c
+++ b/bn_mp_prime_random_ex.c
@@ -123,7 +123,7 @@ int mp_prime_random_ex(mp_int *a, int t, int size, int flags, ltm_prime_callback
 
    err = MP_OKAY;
 error:
-   XFREE(tmp);
+   XFREE(tmp, bsize);
    return err;
 }
 
diff --git a/bn_mp_shrink.c b/bn_mp_shrink.c
index b714fdd98..fa30184aa 100644
--- a/bn_mp_shrink.c
+++ b/bn_mp_shrink.c
@@ -23,7 +23,9 @@ int mp_shrink(mp_int *a)
    }
 
    if (a->alloc != used) {
-      if ((tmp = (mp_digit *) XREALLOC(a->dp, (size_t)used * sizeof(mp_digit))) == NULL) {
+      if ((tmp = (mp_digit *) XREALLOC(a->dp,
+                                       (size_t)a->alloc * sizeof (mp_digit),
+                                       (size_t)used * sizeof(mp_digit))) == NULL) {
          return MP_MEM;
       }
       a->dp    = tmp;
diff --git a/tommath_private.h b/tommath_private.h
index 15c23388a..057f87845 100644
--- a/tommath_private.h
+++ b/tommath_private.h
@@ -29,14 +29,14 @@ extern "C" {
 /* define heap macros */
 #ifndef XMALLOC
 /* default to libc stuff */
-#   define XMALLOC   malloc
-#   define XFREE     free
-#   define XREALLOC  realloc
+#   define XMALLOC(size)                   malloc(size)
+#   define XFREE(mem, size)                free(mem)
+#   define XREALLOC(mem, oldsize, newsize) realloc(mem, newsize)
 #else
 /* prototypes for our heap functions */
-extern void *XMALLOC(size_t n);
-extern void *XREALLOC(void *p, size_t n);
-extern void XFREE(void *p);
+extern void *XMALLOC(size_t size);
+extern void *XREALLOC(void *mem, size_t oldsize, size_t newsize);
+extern void XFREE(void *mem, size_t size);
 #endif
 
 /* ---> Basic Manipulations <--- */