diff --git a/tests/test_partitions.py b/tests/test_partitions.py
index d3292ab5148267db3ce8459e2778b58ca4525204..20ed8fde56f2ff8adc3375ef82b26595bc48f759 100755
--- a/tests/test_partitions.py
+++ b/tests/test_partitions.py
@@ -13,7 +13,7 @@ BS = 512
 
 
 def to_gbytes(size_bytes):
-    return size_bytes/(1024*1024*1024)
+    return int(round(size_bytes/(1024*1024*1024)))
 
 def read_file(fname):
     with open(fname, 'r') as f: