diff --git a/edges.cabal b/edges.cabal
--- a/edges.cabal
+++ b/edges.cabal
@@ -1,5 +1,5 @@
 name: edges
-version: 0.9.0.2
+version: 0.9.1
 category: Graphs
 synopsis: Tools for efficient immutable graphs
 description: A set of tools for constructing immutable graphs which are both memory and performance-efficient.
@@ -38,6 +38,7 @@
     base >=4.7 && <5,
     cereal >=0.5.5 && <0.6,
     contravariant >=1.4 && <2,
+    deepseq >=1.4 && <2,
     deferred-folds >=0.6 && <0.7,
     foldl >=1.4.2 && <2,
     hashable >=1.2 && <2,
diff --git a/library/Edges/Instances.hs b/library/Edges/Instances.hs
--- a/library/Edges/Instances.hs
+++ b/library/Edges/Instances.hs
@@ -16,3 +16,9 @@
 instance Show (NodeCounts a) where show = show . nodeCountsList
 deriving instance Show (Edges a b)
 deriving instance Show (Amount a)
+
+instance NFData (Edges a b) where rnf a = seq a ()
+deriving instance NFData (Node a)
+instance NFData (NodeCounts a) where rnf a = seq a ()
+instance NFData (EdgeCounts a b) where rnf a = seq a ()
+deriving instance NFData (Amount a)
diff --git a/library/Edges/Prelude.hs b/library/Edges/Prelude.hs
--- a/library/Edges/Prelude.hs
+++ b/library/Edges/Prelude.hs
@@ -144,6 +144,10 @@
 -------------------------
 import Data.Text as Exports (Text)
 
+-- deepseq
+-------------------------
+import Control.DeepSeq as Exports
+
 import qualified Data.Vector.Unboxed as UnboxedVector
 
 type UnboxedVector = UnboxedVector.Vector