diff --git a/src/server/MainFastCGI.hs b/src/server/MainFastCGI.hs
index 5e9dd1cee..f57c3f04c 100644
--- a/src/server/MainFastCGI.hs
+++ b/src/server/MainFastCGI.hs
@@ -25,7 +25,7 @@ main = do initFastCGI
           loopFastCGI (handleErrors (handleCGIErrors (fcgiMain r)))
 
 fcgiMain :: DataRef PGF -> CGI CGIResult
-fcgiMain ref = getData PGF.readPGF ref grammarFile >>= cgiMain
+fcgiMain ref = getData (liftIO . PGF.readPGF) ref grammarFile >>= cgiMain
 
 cgiMain :: PGF -> CGI CGIResult
 cgiMain pgf =