diff --git a/src/system/kernel/cache/block_cache.cpp b/src/system/kernel/cache/block_cache.cpp
index 063286ccb9..6e34f1451d 100644
--- a/src/system/kernel/cache/block_cache.cpp
+++ b/src/system/kernel/cache/block_cache.cpp
@@ -3406,6 +3406,9 @@ block_cache_discard(void* _cache, off_t blockNumber, size_t numBlocks)
 	writer.Write();
 		// TODO: this can fail, too!
 
+	blockNumber -= numBlocks;
+		// reset blockNumber to its original value
+
 	for (size_t i = 0; i < numBlocks; i++, blockNumber++) {
 		cached_block* block = (cached_block*)hash_lookup(cache->hash,
 			&blockNumber);