diff --git a/CHANGELOG.md b/CHANGELOG.md
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -1,5 +1,12 @@
 # citeproc changelog
 
+## 0.9.0.1
+
+  * Fix `readAsInt` so it handles negative numbers in strings.
+    `readAsInt` attempts to read strings as integers, but previously
+    it didn't properly handle strings like `"-387"`, which are
+    sometimes used in bibliographies. See jgm/pandoc#10839.
+
 ## 0.9
 
   * Fix handling of `type` conditions in `if` (#151).
diff --git a/citeproc.cabal b/citeproc.cabal
--- a/citeproc.cabal
+++ b/citeproc.cabal
@@ -1,6 +1,6 @@
 cabal-version:       2.2
 name:                citeproc
-version:             0.9
+version:             0.9.0.1
 synopsis:            Generates citations and bibliography from CSL styles.
 description:         citeproc parses CSL style files and uses them to
                      generate a list of formatted citations and bibliography
diff --git a/src/Citeproc/Types.hs b/src/Citeproc/Types.hs
--- a/src/Citeproc/Types.hs
+++ b/src/Citeproc/Types.hs
@@ -1641,7 +1641,13 @@
 
 readAsInt :: Text -> Maybe Int
 readAsInt t =
-  case TR.decimal t of
+  case T.uncons t of
+    Just ('-', t') -> (0 -) <$> readAsDecimal t'
+    Just (c, _) | isDigit c -> readAsDecimal t
+    _ -> Nothing
+  where
+    readAsDecimal s =
+      case TR.decimal s of
       Right (x,t') | T.null t' -> Just x
       _                        -> Nothing