diff --git a/tests/test_noxm.py b/tests/test_noxm.py
index fe3edaf..fc64a2d 100644
--- a/tests/test_noxm.py
+++ b/tests/test_noxm.py
@@ -19,5 +19,7 @@ def test_power2():
     assert xmextras.noxm.power2(0) == 1
     assert xmextras.noxm.power2(1) == 1
     assert xmextras.noxm.power2(2) == 2
+    assert xmextras.noxm.power2(2.5) == 4
     assert xmextras.noxm.power2(3) == 4
+    assert xmextras.noxm.power2(3.5) == 4
     assert xmextras.noxm.power2(65537) == 131072
diff --git a/xmextras/noxm.py b/xmextras/noxm.py
index 6d73427..28a89ac 100644
--- a/xmextras/noxm.py
+++ b/xmextras/noxm.py
@@ -3,6 +3,7 @@
 '''
 
 from datetime import datetime
+from math import frexp, ldexp
 
 J1950_DELTA = 631152000.0
 
@@ -36,7 +37,8 @@ def power2(x):
     Returns the next power of two greater than
     or equal to x.
     '''
-    if x < 1:
+    if x <= 1:
         return 1
 
-    return 1 << (x-1).bit_length()
+    fraction, exponent = frexp(x)
+    return int(ldexp(1, exponent - (fraction == 0.5)))