diff --git a/src/libstore/unix/local-store.hh b/src/libstore/unix/local-store.hh
index 2b6e2e25f..b3d7bd6d0 100644
--- a/src/libstore/unix/local-store.hh
+++ b/src/libstore/unix/local-store.hh
@@ -32,7 +32,6 @@ struct OptimiseStats
 {
     unsigned long filesLinked = 0;
     uint64_t bytesFreed = 0;
-    uint64_t blocksFreed = 0;
 };
 
 struct LocalStoreConfig : virtual LocalFSStoreConfig
diff --git a/src/libstore/unix/optimise-store.cc b/src/libstore/unix/optimise-store.cc
index bedb77849..17b8e4d92 100644
--- a/src/libstore/unix/optimise-store.cc
+++ b/src/libstore/unix/optimise-store.cc
@@ -256,7 +256,6 @@ void LocalStore::optimisePath_(Activity * act, OptimiseStats & stats,
 
     stats.filesLinked++;
     stats.bytesFreed += st.st_size;
-    stats.blocksFreed += st.st_blocks;
 
     if (act)
         act->result(resFileLinked, st.st_size, st.st_blocks);