diff --git a/src/python/m5/ticks.py b/src/python/m5/ticks.py
index 047116a..cdba1e8 100644
--- a/src/python/m5/ticks.py
+++ b/src/python/m5/ticks.py
@@ -25,7 +25,7 @@
 # OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 
 from __future__ import print_function
-from math import ceil
+import decimal
 import six
 if six.PY3:
     long = int
@@ -74,7 +74,8 @@
     # convert the value from time to ticks
     value *= _m5.core.getClockFrequency()
 
-    int_value = int(ceil(value))
+    int_value = int(
+            decimal.Decimal(value).to_integral_value( decimal.ROUND_HALF_UP))
     err = (value - int_value) / value
     if err > frequency_tolerance:
         warn("rounding error > tolerance\n    %f rounded to %d", value,