diff --git a/src/_imagingft.c b/src/_imagingft.c
index 44d2aca55..2427bc685 100644
--- a/src/_imagingft.c
+++ b/src/_imagingft.c
@@ -278,6 +278,7 @@ text_layout_raqm(
         } else if (strcmp(dir, "ttb") == 0) {
             direction = RAQM_DIRECTION_TTB;
 #if !defined(RAQM_VERSION_ATLEAST)
+            /* RAQM_VERSION_ATLEAST was added in Raqm 0.7.0 */
             PyErr_SetString(
                 PyExc_ValueError,
                 "libraqm 0.7 or greater required for 'ttb' direction");