diff --git a/lib/drives.c b/lib/drives.c
index 8fe46a41c..c5a208468 100644
--- a/lib/drives.c
+++ b/lib/drives.c
@@ -593,7 +593,7 @@ guestfs_int_free_drives (guestfs_h *g)
  * Check string parameter matches regular expression
  * C<^[-_[:alnum:]]+$> (in C locale).
  */
-#define VALID_FORMAT_IFACE(str) \
+#define VALID_FORMAT(str) \
   guestfs_int_string_is_valid ((str), 1, 0, \
                                VALID_FLAG_ALPHA|VALID_FLAG_DIGIT, "-_")
 
@@ -790,7 +790,7 @@ guestfs_impl_add_drive_opts (guestfs_h *g, const char *filename,
     return -1;
   }
 
-  if (data.format && !VALID_FORMAT_IFACE (data.format)) {
+  if (data.format && !VALID_FORMAT (data.format)) {
     error (g, _("%s parameter is empty or contains disallowed characters"),
            "format");
     free_drive_servers (data.servers, data.nr_servers);
diff --git a/lib/unit-tests.c b/lib/unit-tests.c
index 62457ccba..0e550cb98 100644
--- a/lib/unit-tests.c
+++ b/lib/unit-tests.c
@@ -434,7 +434,7 @@ test_stringsbuf (void)
 }
 
 /* Use the same macros as in lib/drives.c */
-#define VALID_FORMAT_IFACE(str) \
+#define VALID_FORMAT(str) \
   guestfs_int_string_is_valid ((str), 1, 0, \
                                VALID_FLAG_ALPHA|VALID_FLAG_DIGIT, "-_")
 #define VALID_DISK_LABEL(str) \
@@ -446,18 +446,18 @@ test_stringsbuf (void)
 static void
 test_valid (void)
 {
-  assert (!VALID_FORMAT_IFACE (""));
+  assert (!VALID_FORMAT (""));
   assert (!VALID_DISK_LABEL (""));
   assert (!VALID_HOSTNAME (""));
 
   assert (!VALID_DISK_LABEL ("012345678901234567890"));
 
-  assert (VALID_FORMAT_IFACE ("abc"));
-  assert (VALID_FORMAT_IFACE ("ABC"));
-  assert (VALID_FORMAT_IFACE ("abc123"));
-  assert (VALID_FORMAT_IFACE ("abc123-"));
-  assert (VALID_FORMAT_IFACE ("abc123_"));
-  assert (!VALID_FORMAT_IFACE ("abc123."));
+  assert (VALID_FORMAT ("abc"));
+  assert (VALID_FORMAT ("ABC"));
+  assert (VALID_FORMAT ("abc123"));
+  assert (VALID_FORMAT ("abc123-"));
+  assert (VALID_FORMAT ("abc123_"));
+  assert (!VALID_FORMAT ("abc123."));
 
   assert (VALID_DISK_LABEL ("abc"));
   assert (VALID_DISK_LABEL ("ABC"));