diff --git a/src/system/kernel/device_manager/IOScheduler.cpp b/src/system/kernel/device_manager/IOScheduler.cpp
index 7833c462eb..4e13931cbd 100644
--- a/src/system/kernel/device_manager/IOScheduler.cpp
+++ b/src/system/kernel/device_manager/IOScheduler.cpp
@@ -102,6 +102,7 @@ IOScheduler::IOScheduler(DMAResource* resource)
 	fOperationArray(NULL),
 	fAllocatedRequestOwners(NULL),
 	fRequestOwners(NULL),
+	fBlockSize(0),
 	fPendingOperations(0)
 {
 	mutex_init(&fLock, "I/O scheduler");