diff --git a/.github/workflows/ci.yml b/.github/workflows/ci.yml
index 9cff457..138a2be 100644
--- a/.github/workflows/ci.yml
+++ b/.github/workflows/ci.yml
@@ -4,12 +4,12 @@ on:
   push:
     branches: ["main"]
   pull_request:
-    branches: ["main"]
+    branches: ["main", "1.x"]
   workflow_dispatch:
 
 jobs:
   tests:
-    name: "Python ${{ matrix.python-version }} on ${{ matrix.os }}"
+    name: Python ${{ matrix.python-version }} on ${{ matrix.os }}
     runs-on: ${{ matrix.os }}
 
     strategy:
@@ -25,36 +25,40 @@ jobs:
             python-version: "3.7"
 
     steps:
-      - uses: "actions/checkout@v3"
-      - uses: "actions/setup-python@v4"
+      - uses: actions/checkout@v3
+      - uses: actions/setup-python@v4
         with:
-          python-version: "${{ matrix.python-version }}"
-      - name: "Install dependencies"
+          python-version: ${{ matrix.python-version }}
+      - name: Install dependencies
         run: |
           python -VV
           python -m pip install -r requirements-dev.txt
 
-      - name: "Run tests for ${{ matrix.python-version }} on ${{ matrix.os }}"
+      - name: Run tests for ${{ matrix.python-version }} on ${{ matrix.os }}
         run: python -m pytest
 
       - name: Upload coverage to Codecov
-        uses: "codecov/codecov-action@v3"
+        uses: codecov/codecov-action@v3
+        with:
+          token: ${{ secrets.CODECOV_TOKEN }}
 
   tests-27:
-    name: "Python 2.7 on ubuntu-20.04"
+    name: Python 2.7 on ubuntu-20.04
     runs-on: ubuntu-20.04
     container:
       image: python:2.7-buster
 
     steps:
-      - uses: "actions/checkout@v3"
-      - name: "Install dependencies"
+      - uses: actions/checkout@v3
+      - name: Install dependencies
         run: |
           python -VV
           python -m pip install -r requirements-dev.txt
 
-      - name: "Run tests for Python 2.7 on ubuntu-20.04"
+      - name: Run tests for Python 2.7 on ubuntu-20.04
         run: python -m pytest
 
       - name: Upload coverage to Codecov
-        uses: "codecov/codecov-action@v3"
+        uses: codecov/codecov-action@v3
+        with:
+          token: ${{ secrets.CODECOV_TOKEN }}
diff --git a/johnnydep/pipper.py b/johnnydep/pipper.py
index 1b533bc..f678dcf 100755
--- a/johnnydep/pipper.py
+++ b/johnnydep/pipper.py
@@ -33,10 +33,7 @@
 
 def compute_checksum(target, algorithm="sha256", blocksize=2 ** 13):
     hashtype = getattr(hashlib, algorithm)
-    if algorithm == "blake2b":
-        hash_ = hashtype(digest_size=32)
-    else:
-        hash_ = hashtype()
+    hash_ = hashtype()
     log.debug("computing checksum", target=target, algorithm=algorithm)
     with open(target, "rb") as f:
         for chunk in iter(lambda: f.read(blocksize), b""):
@@ -46,6 +43,18 @@ def compute_checksum(target, algorithm="sha256", blocksize=2 ** 13):
     return result
 
 
+def _warehouse_hash(target):
+    try:
+        blake2b = hashlib.blake2b
+    except AttributeError:
+        # Python < 3.6
+        import pyblake2
+        blake2b = pyblake2.blake2b
+    with open(target, "rb") as f:
+        b2b = blake2b(f.read(), digest_size=32)
+    return b2b.hexdigest()
+
+
 def _get_pip_version():
     # try to get pip version without actually importing pip
     # setuptools gets upset if you import pip before importing setuptools..
@@ -213,7 +222,7 @@ def get(dist_name, index_url=None, env=None, extra_index_url=None, tmpdir=None,
     except ValueError:
         pass
     else:
-        b2b = compute_checksum(whl, "blake2b")
+        b2b = _warehouse_hash(whl)
         path = "/".join([b2b[:2], b2b[2:4], b2b[4:], os.path.basename(whl)])
         urls = {x for x in out.split() if x.startswith("http") and x.endswith(path)}
         if len(urls) == 1:
diff --git a/setup.py b/setup.py
index 7ca4634..35fe91b 100644
--- a/setup.py
+++ b/setup.py
@@ -25,6 +25,7 @@
         "colorama ; python_version < '3.7' or platform_system == 'Windows'",  # structlog
         "cachetools",
         "oyaml",
+        "pyblake2 ; python_version < '3.6'",
         "toml",
         "pip",
         "packaging >= 17, != 22",