diff --git a/vector-algorithms.cabal b/vector-algorithms.cabal
--- a/vector-algorithms.cabal
+++ b/vector-algorithms.cabal
@@ -1,5 +1,5 @@
 name:              vector-algorithms
-version:           0.7.0.3
+version:           0.7.0.4
 license:           BSD3
 license-file:      LICENSE
 author:            Dan Doel
@@ -57,6 +57,9 @@
                  vector >= 0.6 && < 0.13,
                  primitive >=0.3 && <0.7,
                  bytestring >= 0.9 && < 1.0
+
+  if ! impl (ghc >= 7.8)
+    build-depends: tagged >= 0.4 && < 0.9
 
   exposed-modules:
     Data.Vector.Algorithms.Optimal