diff --git a/devtools/environment.yml b/devtools/environment.yml
index ee42447..e3da90e 100644
--- a/devtools/environment.yml
+++ b/devtools/environment.yml
@@ -12,4 +12,4 @@ dependencies:
   - codecov
   - pip
   - pip:
-    - propka==3.1
+    - propka==3.2
diff --git a/propkatraj/propkatraj.py b/propkatraj/propkatraj.py
index 5cc0b41..eb86c19 100644
--- a/propkatraj/propkatraj.py
+++ b/propkatraj/propkatraj.py
@@ -132,7 +132,7 @@ def _single_frame(self):
             # extract pka estimates from each residue
             self._pkas.append([g.pka_value for g in groups])
             if self._columns is None:
-                self._columns = [g.atom.resNumb for g in groups]
+                self._columns = [g.atom.res_num for g in groups]
         finally:
             # deallocate stream
             pstream.close(force=True)
diff --git a/pyproject.toml b/pyproject.toml
index 128350e..d6db1e1 100644
--- a/pyproject.toml
+++ b/pyproject.toml
@@ -37,7 +37,7 @@ dependencies = [
      "MDAnalysis>=2.1.0",
     "numpy",
     "pandas",
-    "propka==3.1",
+    "propka>=3.2",
 ]
 keywords = [
     "molecular simulations",