diff --git a/union_cache.go b/cacheOnReadFs.go
similarity index 100%
rename from union_cache.go
rename to cacheOnReadFs.go
diff --git a/union_test.go b/composite_test.go
similarity index 100%
rename from union_test.go
rename to composite_test.go
diff --git a/union_cow.go b/copyOnWriteFs.go
similarity index 100%
rename from union_cow.go
rename to copyOnWriteFs.go
diff --git a/union.go b/unionFile.go
similarity index 100%
rename from union.go
rename to unionFile.go