diff --git a/partitura/utils/globals.py b/partitura/utils/globals.py
index b9e9bbbc..e53e3174 100644
--- a/partitura/utils/globals.py
+++ b/partitura/utils/globals.py
@@ -258,7 +258,7 @@
     "A#",
 ]
 
-TIME_UNITS = ["beat", "quarter", "sec", "div"]
+TIME_UNITS = ["beat", "quarter", "sec", "div", "tick"]
 
 NOTE_NAME_PATT = re.compile(r"([A-G]{1})([xb\#]*)(\d+)")
 
diff --git a/partitura/utils/music.py b/partitura/utils/music.py
index 777189ec..9c01e6df 100644
--- a/partitura/utils/music.py
+++ b/partitura/utils/music.py
@@ -1145,7 +1145,7 @@ def compute_pianoroll(
     if time_div == "auto":
         if onset_unit in ("onset_beat", "onset_quarter", "onset_sec"):
             time_div = 8
-        elif onset_unit == "onset_div":
+        elif onset_unit in ("onset_div", "onset_tick"):
             time_div = 1
     else:
         time_div = int(time_div)