diff --git a/pyproject.toml b/pyproject.toml
index a89a206666..d33b27a99c 100644
--- a/pyproject.toml
+++ b/pyproject.toml
@@ -141,12 +141,29 @@ ignore_missing_imports = true
   ignore_errors = true
   ignore_missing_imports = true
 
-  # pytest (which we depend on) optionally imports numpy, which requires Python 3.8 in
-  # recent versions. mypy still imports its .pyi file, which has positional-only
-  # arguments, which don't work in 3.7, which causes mypy to bail out early if you have
-  # numpy installed.
+  # Spack imports a number of external packages, and they *may* require Python 3.8 or
+  # higher in recent versions. This can cause mypy to fail because we check for 3.7
+  # compatibility. We could restrict mypy to run for the oldest supported version (3.7),
+  # but that means most developers won't be able to run mypy, which means it'll fail
+  # more in CI. Instead, we exclude these imported packages from mypy checking.
   [[tool.mypy.overrides]]
-  module = 'numpy'
+  module = [
+      'IPython',
+      'altgraph',
+      'attr',
+      'boto3',
+      'botocore',
+      'distro',
+      'jinja2',
+      'jsonschema',
+      'macholib',
+      'markupsafe',
+      'numpy',
+      'pyristent',
+      'pytest',
+      'ruamel.yaml',
+      'six',
+  ]
   follow_imports = 'skip'
   follow_imports_for_stubs = true