diff --git a/lib/pure/collections/sets.nim b/lib/pure/collections/sets.nim
index aa4919884c..20f73ded3e 100644
--- a/lib/pure/collections/sets.nim
+++ b/lib/pure/collections/sets.nim
@@ -18,7 +18,7 @@
 ## that ``=`` performs a copy of the set.
 
 import
-  os, hashes, math
+  hashes, math
 
 {.pragma: myShallow.}
 when not defined(nimhygiene):