diff --git a/Changelog.md b/Changelog.md
--- a/Changelog.md
+++ b/Changelog.md
@@ -1,3 +1,7 @@
+### 0.9.1.1
+
+- yY handler must be strict against exceptions in safeYYHandler.
+
 ### 0.9.1.0
 
 - Do not write into service event channel when Nginx is exiting.
diff --git a/NgxExport.hs b/NgxExport.hs
--- a/NgxExport.hs
+++ b/NgxExport.hs
@@ -436,8 +436,9 @@
     Ptr (Ptr NgxStrType) -> Ptr CInt ->
     Ptr (StablePtr L.ByteString) -> IO CUInt
 yY f x (I n) p pl spd = do
-    (s, (r, _)) <- safeYYHandler $
-        flip (,) (0, False) . f <$> B.unsafePackCStringLen (x, n)
+    (s, (r, _)) <- safeYYHandler $ do
+        s <- f <$> B.unsafePackCStringLen (x, n)
+        fmap (flip (,) (0, False)) $ return $! s
     pokeLazyByteString s p pl spd
     return r
 
diff --git a/ngx-export.cabal b/ngx-export.cabal
--- a/ngx-export.cabal
+++ b/ngx-export.cabal
@@ -1,5 +1,5 @@
 name:                       ngx-export
-version:                    0.9.1.0
+version:                    0.9.1.1
 synopsis:                   Helper module for Nginx haskell module
 description:                Helper module for
         <http://github.com/lyokha/nginx-haskell-module Nginx haskell module>