diff --git a/src/main.c b/src/main.c
index ebbef40a..7418e61d 100644
--- a/src/main.c
+++ b/src/main.c
@@ -14,15 +14,9 @@ void pic_load_piclib(pic_state *);
 static pic_value
 pic_features(pic_state *pic)
 {
-  pic_value features = pic_nil_value();
-
   pic_get_args(pic, "");
 
-  pic_push(pic, pic_sym_value(pic_intern_cstr(pic, "r7rs")), features);
-  pic_push(pic, pic_sym_value(pic_intern_cstr(pic, "ieee-float")), features);
-  pic_push(pic, pic_sym_value(pic_intern_cstr(pic, "picrin")), features);
-
-  return features;
+  return pic->features;
 }
 
 static pic_value
@@ -42,6 +36,8 @@ pic_libraries(pic_state *pic)
 void
 pic_init_picrin(pic_state *pic)
 {
+  pic_add_feature(pic, "r7rs");
+
   pic_deflibrary (pic, "(picrin library)") {
     pic_defun(pic, "libraries", pic_libraries);
   }
diff --git a/t/r7rs-tests.scm b/t/r7rs-tests.scm
index 6143a555..a5eeb2a6 100644
--- a/t/r7rs-tests.scm
+++ b/t/r7rs-tests.scm
@@ -48,6 +48,41 @@
 
 (test-begin "R7RS")
 
+(test-begin "cond-expand")
+
+(test #t (cond-expand
+          (r7rs #t)
+          (else #f)))
+(test #t (cond-expand
+          ((library (scheme write)) #t)
+          (else #f)))
+(test #t (cond-expand
+          ((not r6rs) #t)
+          (else #f)))
+(test #t (cond-expand
+          ((and r7rs (library (picrin test))) #t)
+          (else #f)))
+(test #t (cond-expand
+          ((or r6rs r7rs) #t)
+          (else #f)))
+(cond-expand
+ (r7rs (test #t #t))
+ (else (test #t #f)))
+(cond-expand
+ ((library (scheme write)) (test #t #t))
+ (else (test #t #f)))
+(cond-expand
+ ((not r6rs) (test #t #t))
+ (else (test #t #f)))
+(cond-expand
+ ((and r7rs (library (picrin test))) (test #t #t))
+ (else (test #t #f)))
+(cond-expand
+ ((or r6rs r7rs) (test #t #t))
+ (else (test #t #f)))
+
+(test-end)
+
 (test-begin "4.1 Primitive expression types")
 
 (let ()