diff --git a/sexp.h b/sexp.h
index 21527fa..c6d41f1 100644
--- a/sexp.h
+++ b/sexp.h
@@ -49,9 +49,9 @@ extern sexp_t *sexp_cons(sexp_t *head, sexp_t *tail);
     })
 
 #define sexp_stringp(x) ({						\
-    sexp_t *__x = (x);							\
-    sexp_simple_stringp(__x) || ((__x != NULL) && (__x->kind == SEXP_DISPLAY_HINT)); \
-  }
+      sexp_t *__x = (x);						\
+      sexp_simple_stringp(__x) || ((__x != NULL) && (__x->kind == SEXP_DISPLAY_HINT)); \
+    })
 
 #define sexp_pairp(x) ({				\
       sexp_t *__x = (x);				\