diff --git a/Utils.cpp b/Utils.cpp
index 51ef4c4..2dd9ae8 100644
--- a/Utils.cpp
+++ b/Utils.cpp
@@ -504,7 +504,7 @@
         goto done;
     }
 
-    if ((ioctl(fd, BLKGETSIZE, nr_sec)) == -1) {
+    if ((ioctl(fd, BLKGETSIZE, &nr_sec)) == -1) {
         PLOG(ERROR) << "Failed to determine size of " << path;
         goto done;
     }