diff --git a/library/StmContainers/Map.hs b/library/StmContainers/Map.hs
--- a/library/StmContainers/Map.hs
+++ b/library/StmContainers/Map.hs
@@ -11,6 +11,7 @@
     reset,
     unfoldlM,
     listT,
+    listTNonAtomic,
   )
 where
 
@@ -111,5 +112,11 @@
 -- Stream the associations passively.
 {-# INLINE listT #-}
 listT :: Map key value -> ListT STM (key, value)
-listT (Map hamt) =
-  fmap (\(Product2 k v) -> (k, v)) (A.listT hamt)
+listT (Map hamt) = fmap (\(Product2 k v) -> (k, v)) (A.listT hamt)
+
+-- |
+-- Stream the associations passively.
+-- Data may be inconsistent/out of date.
+{-# INLINE listTNonAtomic #-}
+listTNonAtomic :: Map key value -> ListT IO (key, value)
+listTNonAtomic (Map hamt) = fmap (\(Product2 k v) -> (k, v)) (A.listTNonAtomic hamt)
diff --git a/stm-containers.cabal b/stm-containers.cabal
--- a/stm-containers.cabal
+++ b/stm-containers.cabal
@@ -1,7 +1,7 @@
 cabal-version: 3.0
-name:          stm-containers
-version:       1.2.0.3
-synopsis:      Containers for STM
+name: stm-containers
+version: 1.2.1
+synopsis: Containers for STM
 description:
   This library is based on an STM-specialized implementation of
   Hash Array Mapped Trie.
@@ -13,24 +13,22 @@
   For details on performance of the library, which are a bit outdated, see
   <http://nikita-volkov.github.io/stm-containers/ this blog post>.
 
-category:      Data Structures, STM, Concurrency
-homepage:      https://github.com/nikita-volkov/stm-containers
-bug-reports:   https://github.com/nikita-volkov/stm-containers/issues
-author:        Nikita Volkov <nikita.y.volkov@mail.ru>
-maintainer:    Nikita Volkov <nikita.y.volkov@mail.ru>
-copyright:     (c) 2014, Nikita Volkov
-license:       MIT
-license-file:  LICENSE
+category: Data Structures, STM, Concurrency
+homepage: https://github.com/nikita-volkov/stm-containers
+bug-reports: https://github.com/nikita-volkov/stm-containers/issues
+author: Nikita Volkov <nikita.y.volkov@mail.ru>
+maintainer: Nikita Volkov <nikita.y.volkov@mail.ru>
+copyright: (c) 2014, Nikita Volkov
+license: MIT
+license-file: LICENSE
 
 source-repository head
-  type:     git
+  type: git
   location: git://github.com/nikita-volkov/stm-containers.git
 
 library
-  hs-source-dirs:     library
+  hs-source-dirs: library
   default-extensions:
-    NoImplicitPrelude
-    NoMonomorphismRestriction
     Arrows
     BangPatterns
     ConstraintKinds
@@ -52,6 +50,8 @@
     MagicHash
     MultiParamTypeClasses
     MultiWayIf
+    NoImplicitPrelude
+    NoMonomorphismRestriction
     OverloadedStrings
     ParallelListComp
     PatternGuards
@@ -68,29 +68,27 @@
     TypeOperators
     UnboxedTuples
 
-  default-language:   Haskell2010
+  default-language: Haskell2010
   exposed-modules:
     StmContainers.Bimap
     StmContainers.Map
     StmContainers.Multimap
     StmContainers.Set
 
-  other-modules:      StmContainers.Prelude
+  other-modules: StmContainers.Prelude
   build-depends:
-    , base >=4.9 && <5
-    , deferred-folds >=0.9 && <0.10
-    , focus >=1.0.1.4 && <1.1
-    , hashable >=1.4 && <2
-    , list-t >=1.0.1 && <1.1
-    , stm-hamt >=1.2 && <1.3
-    , transformers >=0.5 && <0.7
+    base >=4.9 && <5,
+    deferred-folds >=0.9 && <0.10,
+    focus >=1.0.1.4 && <1.1,
+    hashable >=1.4 && <2,
+    list-t >=1.0.1 && <1.1,
+    stm-hamt >=1.2.1 && <1.3,
+    transformers >=0.5 && <0.7,
 
 test-suite test
-  type:               exitcode-stdio-1.0
-  hs-source-dirs:     test
+  type: exitcode-stdio-1.0
+  hs-source-dirs: test
   default-extensions:
-    NoImplicitPrelude
-    NoMonomorphismRestriction
     Arrows
     BangPatterns
     ConstraintKinds
@@ -112,6 +110,8 @@
     MagicHash
     MultiParamTypeClasses
     MultiWayIf
+    NoImplicitPrelude
+    NoMonomorphismRestriction
     OverloadedStrings
     ParallelListComp
     PatternGuards
@@ -128,22 +128,22 @@
     TypeOperators
     UnboxedTuples
 
-  default-language:   Haskell2010
-  main-is:            Main.hs
+  default-language: Haskell2010
+  main-is: Main.hs
   other-modules:
     Suites.Bimap
     Suites.Map
     Suites.Map.Update
 
   build-depends:
-    , deferred-folds
-    , focus
-    , foldl >=1.4 && <2
-    , free >=4.6 && <6
-    , list-t
-    , quickcheck-instances >=0.3.29.1 && <0.4
-    , rerebase >=1 && <2
-    , stm-containers
-    , tasty >=0.12 && <2
-    , tasty-hunit >=0.10.0.3 && <0.11
-    , tasty-quickcheck >=0.10.2 && <0.11
+    deferred-folds,
+    focus,
+    foldl >=1.4 && <2,
+    free >=4.6 && <6,
+    list-t,
+    quickcheck-instances >=0.3.29.1 && <0.4,
+    rerebase >=1 && <2,
+    stm-containers,
+    tasty >=0.12 && <2,
+    tasty-hunit >=0.10.0.3 && <0.11,
+    tasty-quickcheck >=0.10.2 && <0.11,