diff --git a/org.eclipse.jgit/src/org/eclipse/jgit/internal/storage/dfs/DfsBlockCache.java b/org.eclipse.jgit/src/org/eclipse/jgit/internal/storage/dfs/DfsBlockCache.java
index a96be4a7f..03947d839 100644
--- a/org.eclipse.jgit/src/org/eclipse/jgit/internal/storage/dfs/DfsBlockCache.java
+++ b/org.eclipse.jgit/src/org/eclipse/jgit/internal/storage/dfs/DfsBlockCache.java
@@ -418,8 +418,11 @@ public final class DfsBlockCache {
 
 	private void creditSpace(int credit, DfsStreamKey key) {
 		clockLock.lock();
-		getStat(liveBytes, key).addAndGet(-credit);
-		clockLock.unlock();
+		try {
+			getStat(liveBytes, key).addAndGet(-credit);
+		} finally {
+			clockLock.unlock();
+		}
 	}
 
 	@SuppressWarnings("unchecked")