diff --git a/.github/workflows/wheels.yml b/.github/workflows/wheels.yml
index 2c731a70c..3d61bf1d6 100644
--- a/.github/workflows/wheels.yml
+++ b/.github/workflows/wheels.yml
@@ -39,7 +39,7 @@ jobs:
     runs-on: ${{ matrix.os }}
 
     steps:
-      - uses: Wandalen/wretry.action@v1.0.36
+      - uses: Wandalen/wretry.action@v1.2.0
         with:
           action: actions/checkout@v3
           with: |
diff --git a/setup.py b/setup.py
index f0c3bcc8b..89f3a33a4 100644
--- a/setup.py
+++ b/setup.py
@@ -16,13 +16,13 @@
 
 this_directory = os.path.abspath(os.path.dirname(__file__))
 
-with open(os.path.join("include/mitsuba/mitsuba.h")) as f:
+with open(os.path.join(this_directory, "include/mitsuba/mitsuba.h")) as f:
     mi_version_regex = re.compile(
         r"^\s*#\s*define\s+MI_VERSION_([A-Z]+)\s+(.*)$", re.MULTILINE)
     matches = dict(mi_version_regex.findall(f.read()))
     mitsuba_version = "{MAJOR}.{MINOR}.{PATCH}".format(**matches)
 
-with open(os.path.join("ext/drjit/include/drjit/fwd.h")) as f:
+with open(os.path.join(this_directory, "ext/drjit/include/drjit/fwd.h")) as f:
     drjit_version_regex = re.compile(
         r"^\s*#\s*define\s+DRJIT_VERSION_([A-Z]+)\s+(.*)$", re.MULTILINE)
     matches = dict(drjit_version_regex.findall(f.read()))