diff --git a/piclib/CMakeLists.txt b/piclib/CMakeLists.txt
index 497d8cd1..49f1c4b3 100644
--- a/piclib/CMakeLists.txt
+++ b/piclib/CMakeLists.txt
@@ -1,5 +1,6 @@
 list(APPEND PICLIB_SCHEME_LIBS
   ${PROJECT_SOURCE_DIR}/piclib/built-in.scm
+  ${PROJECT_SOURCE_DIR}/piclib/picrin/dictionary.scm
   ${PROJECT_SOURCE_DIR}/piclib/srfi/1.scm
   ${PROJECT_SOURCE_DIR}/piclib/srfi/8.scm
   ${PROJECT_SOURCE_DIR}/piclib/srfi/26.scm
diff --git a/piclib/picrin/dictionary.scm b/piclib/picrin/dictionary.scm
new file mode 100644
index 00000000..ac23f8ab
--- /dev/null
+++ b/piclib/picrin/dictionary.scm
@@ -0,0 +1,31 @@
+(define-library (picrin dictionary)
+  (import (scheme base))
+
+  (define (dictionary->plist dict)
+    (error "not implemented"))
+
+  (define (plist->dictionary plist)
+    (let ((dict (make-dictionary)))
+      (do ((kv plist (cddr kv)))
+          ((null? kv)
+           dict)
+        (dictionary-set! dict (car kv) (cadr kv)))))
+
+  (define (dictionary->alist dict)
+    (error "not implemented"))
+
+  (define (alist->dictionary alist)
+    (let ((dict (make-dictionary)))
+      (do ((kv alist (cdr kv)))
+          ((null? kv)
+           dict)
+        (dictionary-set! dict (car kv) (cdr kv)))))
+
+  (define (dictionary . plist)
+    (plist->dictionary plist))
+
+  (export dictionary
+          dictionary->plist
+          plist->dictionary
+          dictionary->alist
+          alist->dictionary))