diff --git a/tests/suites/helpers.function b/tests/suites/helpers.function
index f416b30..cbe3fa0 100644
--- a/tests/suites/helpers.function
+++ b/tests/suites/helpers.function
@@ -95,7 +95,7 @@
  * You must set \p pointer to \c NULL before calling this macro and
  * put `mbedtls_free( pointer )` in the test's cleanup code.
  *
- * If \p size is zero, the resulting \p pointer will be \c NULL.
+ * If \p length is zero, the resulting \p pointer will be \c NULL.
  * This is usually what we want in tests since API functions are
  * supposed to accept null pointers when a buffer size is zero.
  *
@@ -105,20 +105,21 @@
  * \param pointer   An lvalue where the address of the allocated buffer
  *                  will be stored.
  *                  This expression may be evaluated multiple times.
- * \param size      Buffer size to allocate in bytes.
+ * \param length    Number of elements to allocate.
  *                  This expression may be evaluated multiple times.
  *
  */
-#define ASSERT_ALLOC( pointer, size )                           \
-    do                                                          \
-    {                                                           \
-        TEST_ASSERT( ( pointer ) == NULL );                     \
-        if( ( size ) != 0 )                                     \
-        {                                                       \
-            ( pointer ) = mbedtls_calloc( 1, ( size ) );        \
-            TEST_ASSERT( ( pointer ) != NULL );                 \
-        }                                                       \
-    }                                                           \
+#define ASSERT_ALLOC( pointer, length )                           \
+    do                                                            \
+    {                                                             \
+        TEST_ASSERT( ( pointer ) == NULL );                       \
+        if( ( length ) != 0 )                                     \
+        {                                                         \
+            ( pointer ) = mbedtls_calloc( sizeof( *( pointer ) ), \
+                                          ( length ) );           \
+            TEST_ASSERT( ( pointer ) != NULL );                   \
+        }                                                         \
+    }                                                             \
     while( 0 )
 
 /** Compare two buffers and fail the test case if they differ.