diff --git a/.travis.yml b/.travis.yml
index 72be81d4..42b63c99 100644
--- a/.travis.yml
+++ b/.travis.yml
@@ -18,6 +18,12 @@ matrix:
     # core
     - python: "3.6"
       env: TOX_POSARGS="-e py36-core"
+    #
+    # pypy3 testing
+    #
+    # core
+    - python: "pypy3"
+      env: TOX_POSARGS="-e pypy3-core"
 cache:
   - pip: true
 install:
diff --git a/setup.py b/setup.py
index a89f4aca..a59d9eec 100644
--- a/setup.py
+++ b/setup.py
@@ -62,5 +62,6 @@ setup(
         'Programming Language :: Python :: 3',
         'Programming Language :: Python :: 3.5',
         'Programming Language :: Python :: 3.6',
+        'Programming Language :: Python :: Implementation :: PyPy3',
     ],
 )
diff --git a/tox.ini b/tox.ini
index 02772752..9b1727e7 100644
--- a/tox.ini
+++ b/tox.ini
@@ -1,6 +1,6 @@
 [tox]
 envlist=
-    py{35,36}-core
+    py{35,36,py3}-core
     lint
 
 [isort]
@@ -25,6 +25,7 @@ commands=
 basepython =
     py35: python3.5
     py36: python3.6
+    pypy3: pypy3
 extras=test
 
 [testenv:lint]