diff --git a/examples/map.modal b/examples/map.modal
new file mode 100644
index 0000000..ba064f7
--- /dev/null
+++ b/examples/map.modal
@@ -0,0 +1,8 @@
+<> (foo ?x) (?x)
+<> (map ?x (list ?l)) (map/l map/x ?x ?l)
+<> (map/x ?x (?h ?t)) (?x ?h (map/x ?x ?t))
+<> (map/x ?x (?h)) (map/r (?x ?h))
+<> (?h (map/r ?t)) (?map/r (?h ?t))
+<> (map/l map/r ?l) (list ?l)
+
+map foo (list (1 (2 (3 (4 (5))))))
\ No newline at end of file
diff --git a/src/modal.c b/src/modal.c
index 73f7656..0e7887e 100644
--- a/src/modal.c
+++ b/src/modal.c
@@ -177,6 +177,7 @@ rewrite(void)
 			if(s[0] == '?' && s[1] == '(') {
 				r = &lambda;
 				s = create_rule(&lambda, -1, s) + 1;
+				while((c = *s) && c <= ' ') s++;
 				if((res = match_rule(&lambda, s)) != NULL)
 					return write_rule(&lambda, last, res);
 			}