diff --git a/src/filter.c b/src/filter.c
index 3164191..6a932d1 100644
--- a/src/filter.c
+++ b/src/filter.c
@@ -78,6 +78,9 @@ void filter_init (void)
                  * comments.
                  */
                 s = buf;
+                /* skip leading whitespace */
+                while (*s && isspace ((unsigned char) *s))
+                        ++s;
                 while (*s) {
                         if (isspace ((unsigned char) *s))
                                 break;