diff --git a/piker/calc.py b/piker/calc.py
index 3d080087..0c891852 100644
--- a/piker/calc.py
+++ b/piker/calc.py
@@ -9,10 +9,12 @@ def humanize(number):
     """Convert large numbers to something with at most 3 digits and
     a letter suffix (eg. k: thousand, M: million, B: billion).
     """
-    if number <= 0:
+    if not number or number <= 0:
         return number
     mag2suffix = {3: 'k', 6: 'M', 9: 'B'}
     mag = math.floor(math.log(number, 10))
+    if mag < 3:
+        return number
     maxmag = max(itertools.takewhile(lambda key: mag >= key, mag2suffix))
     return "{:.3f}{}".format(number/10**maxmag, mag2suffix[maxmag])