diff --git a/.github/workflows/ci.yml b/.github/workflows/ci.yml
index d75a92e..0efc79a 100644
--- a/.github/workflows/ci.yml
+++ b/.github/workflows/ci.yml
@@ -25,7 +25,7 @@ jobs:
     runs-on: ${{ matrix.platform }}
     strategy:
       matrix:
-        python-version: [3.8, 3.9, '3.10']
+        python-version: [3.7, 3.8, 3.9, '3.10']
         platform: [ubuntu-latest]
     steps:
     - uses: actions/checkout@v2
diff --git a/README.md b/README.md
index 712ffe3..de06aa7 100644
--- a/README.md
+++ b/README.md
@@ -97,8 +97,6 @@ asyncio.run(main_async())
 [adding fonts]: #adding-fonts
 
 This package has a built-in list of supported fonts in its [config].
-The list indicates these fonts passed the [visual test],
-with possibly tweaked configurations.
 
 Fonts not in the known list are still processed
 with the default configuration,
@@ -110,10 +108,11 @@ the following process is recommended:
 1. Find the font names.
    Running the `add-chws` with `--print-name` option can print them.
 2. Add them to the [config].
-3. Build the font and run the [Visual Test].
+3. (Optional) Build the font and run the [Visual Test].
    This step is optional
-   because this package automatically avoids glyph collisions.
-4. Tweak the [config] if needed.
+   because this package automatically avoids glyph collisions
+   by computing glyph outlines.
+4. (Optional) Tweak the [config] if needed.
 
 [config]: src/chws_tool/config.py
 
diff --git a/setup.py b/setup.py
index e049128..72ea617 100644
--- a/setup.py
+++ b/setup.py
@@ -44,7 +44,7 @@
             "pytype",
         ],
     },
-    python_requires=">=3.8",
+    python_requires=">=3.7",
 
     # this is for type checker to use our inline type hints:
     # https://www.python.org/dev/peps/pep-0561/#id18
diff --git a/tox.ini b/tox.ini
index 20a18ef..2ea2f16 100644
--- a/tox.ini
+++ b/tox.ini
@@ -11,7 +11,7 @@
 ;   $ export TOXENV=py39
 ;   $ tox
 ;     # If present use $TOXENV environment variable
-envlist = lint, py3{8,9,10}
+envlist = lint, py3{7,8,9,10}
 
 ; if any of the requested python interpreters is unavailable (e.g. on the local dev
 ; workstation), the tests are skipped and tox won't return an error