diff --git a/secdiscard.cpp b/secdiscard.cpp
index 0ff05d6..4659eed 100644
--- a/secdiscard.cpp
+++ b/secdiscard.cpp
@@ -147,6 +147,10 @@
             if (!overwrite_with_zeros(fs_fd.get(), range[0], range[1])) return false;
         }
     }
+    // Should wait for overwrites completion. Otherwise after unlink(),
+    // filesystem can allocate these blocks and IO can be reordered, resulting
+    // in making zero blocks to filesystem blocks.
+    fsync(fs_fd.get());
     return true;
 }