diff --git a/src/args/lint-python/builder.sh b/src/args/lint-python/builder.sh
index 3bf7388a..e310b0f2 100644
--- a/src/args/lint-python/builder.sh
+++ b/src/args/lint-python/builder.sh
@@ -1,5 +1,13 @@
 # shellcheck shell=bash
 
+function get_package_name {
+  local package_path="${1}"
+  local package_dir
+
+  : && package_dir="$(basename "${envSrc#*--}")" \
+    && echo "${package_dir//-/_}"
+}
+
 function main {
   # If you do `import XXX` in your python code and the structure is like this:
   #   /path/to/XXX
@@ -12,7 +20,7 @@ function main {
   local python_dirs
   local python_dir
 
-  package_name="$(basename "${envSrc#*-}")" \
+  package_name="$(get_package_name "${envSrc}")" \
     && info Running mypy over: "${package_path}", package "${package_name}" \
     && if ! test -e "${package_path}/py.typed"; then
       error This is not a mypy package, py.typed missing
diff --git a/src/args/project-path/default.nix b/src/args/project-path/default.nix
index c545e6b7..9f9ecc62 100644
--- a/src/args/project-path/default.nix
+++ b/src/args/project-path/default.nix
@@ -13,7 +13,7 @@ then
     name =
       if rel == "/"
       then "src"
-      else builtins.baseNameOf rel;
+      else builtins.replaceStrings ["/"] ["-"] rel;
     path = (builtins.unsafeDiscardStringContext projectSrc) + rel;
   })
 else abort "projectPath arguments must start with: /, currently it is: ${rel}"