diff --git a/src/core/Base32.cj b/src/Base32.cj
similarity index 99%
rename from src/core/Base32.cj
rename to src/Base32.cj
index 4c946a7..41606af 100644
--- a/src/core/Base32.cj
+++ b/src/Base32.cj
@@ -1,4 +1,4 @@
-package simcu::otp.core
+package simcu::otp
 
 import std.collection.*
 
diff --git a/src/core/HmacSha1.cj b/src/HmacSha1.cj
similarity index 98%
rename from src/core/HmacSha1.cj
rename to src/HmacSha1.cj
index 8717949..9164ebb 100644
--- a/src/core/HmacSha1.cj
+++ b/src/HmacSha1.cj
@@ -1,4 +1,4 @@
-package simcu::otp.core
+package simcu::otp
 
 import stdx.crypto.digest.SHA1
 
diff --git a/src/core/Hotp.cj b/src/Hotp.cj
similarity index 98%
rename from src/core/Hotp.cj
rename to src/Hotp.cj
index b1a0b05..26436ae 100644
--- a/src/core/Hotp.cj
+++ b/src/Hotp.cj
@@ -1,4 +1,4 @@
-package simcu::otp.core
+package simcu::otp
 
 /**
  * HOTP（HMAC-based One-Time Password, RFC 4226）。
diff --git a/src/Otp.cj b/src/Otp.cj
deleted file mode 100644
index 6d56f66..0000000
--- a/src/Otp.cj
+++ /dev/null
@@ -1,3 +0,0 @@
-package simcu::otp
-
-public import simcu::otp.core.*
diff --git a/src/core/OtpUri.cj b/src/OtpUri.cj
similarity index 98%
rename from src/core/OtpUri.cj
rename to src/OtpUri.cj
index 01aa0fc..2d28fbc 100644
--- a/src/core/OtpUri.cj
+++ b/src/OtpUri.cj
@@ -1,4 +1,4 @@
-package simcu::otp.core
+package simcu::otp
 
 import std.random.*
 import std.convert.*
diff --git a/src/core/Totp.cj b/src/Totp.cj
similarity index 99%
rename from src/core/Totp.cj
rename to src/Totp.cj
index 0a8fe9f..6255806 100644
--- a/src/core/Totp.cj
+++ b/src/Totp.cj
@@ -1,4 +1,4 @@
-package simcu::otp.core
+package simcu::otp
 
 import std.time.*