diff --git a/cabal-docspec/Changelog.md b/cabal-docspec/Changelog.md
index a65ff67..437e738 100644
--- a/cabal-docspec/Changelog.md
+++ b/cabal-docspec/Changelog.md
@@ -1,3 +1,7 @@
+# 0.0.0.20240703
+
+- Fix "Project Unit Id" bug
+
 # 0.0.0.20240702
 
 - Support `cabal-install-3.12` changed store directory logic
diff --git a/cabal-docspec/cabal-docspec.cabal b/cabal-docspec/cabal-docspec.cabal
index b4e669e..180e7c7 100644
--- a/cabal-docspec/cabal-docspec.cabal
+++ b/cabal-docspec/cabal-docspec.cabal
@@ -1,6 +1,6 @@
 cabal-version:      2.2
 name:               cabal-docspec
-version:            0.0.0.20240702
+version:            0.0.0.20240703
 synopsis:           Run examples in your docs
 category:           Development
 description:
diff --git a/peura/src/Peura/GHC.hs b/peura/src/Peura/GHC.hs
index 42dac4a..051bc1d 100644
--- a/peura/src/Peura/GHC.hs
+++ b/peura/src/Peura/GHC.hs
@@ -87,12 +87,14 @@ getGhcInfo tracer ghc = do
                 lookup "LibDir" info
             libDir <- makeAbsoluteFilePath libDirStr
 
-            let pui :: String
-                pui = fromMaybe "" $ lookup "Project Unit Id" info
-
-            let prefix = "ghc-" ++ prettyShow ver ++ "-"
-            unless (L.isPrefixOf prefix pui) $
-                die tracer $ prefix ++ " is not prefix of Project Unit Id: " ++ pui
+            pui <- case lookup "Project Unit Id" info of
+                Nothing -> return ""
+                Just pui -> do
+                    let prefix = "ghc-" ++ prettyShow ver ++ "-"
+                    unless (L.isPrefixOf prefix pui) $
+                        die tracer $ prefix ++ " is not prefix of Project Unit Id: " ++ pui
+
+                    return pui
 
             return GhcInfo
                 { ghcPath     = ghc