diff --git a/hledger-lib/hledger-lib.cabal b/hledger-lib/hledger-lib.cabal
index 09477620f..8b7f7393b 100644
--- a/hledger-lib/hledger-lib.cabal
+++ b/hledger-lib/hledger-lib.cabal
@@ -83,6 +83,7 @@ library
     , uglymemo
     , utf8-string >=0.3.5 && <1.1
     , HUnit
+    , extra
   exposed-modules:
       Hledger
       Hledger.Data
@@ -171,6 +172,7 @@ test-suite doctests
     , uglymemo
     , utf8-string >=0.3.5 && <1.1
     , HUnit
+    , extra
     , doctest >=0.8
     , Glob >=0.7
   other-modules:
@@ -259,6 +261,7 @@ test-suite hunittests
     , uglymemo
     , utf8-string >=0.3.5 && <1.1
     , HUnit
+    , extra
     , hledger-lib
     , test-framework
     , test-framework-hunit
diff --git a/hledger-lib/package.yaml b/hledger-lib/package.yaml
index 38acd124a..ab26e46f6 100644
--- a/hledger-lib/package.yaml
+++ b/hledger-lib/package.yaml
@@ -70,6 +70,7 @@ dependencies:
 - uglymemo
 - utf8-string >=0.3.5 && <1.1
 - HUnit
+- extra
 # for ledger-parse:
 #- parsers >= 0.5
 #- system-filepath