diff --git a/inline-r.cabal b/inline-r.cabal
--- a/inline-r.cabal
+++ b/inline-r.cabal
@@ -1,5 +1,5 @@
 name:                inline-r
-version:             0.9.0.0
+version:             0.9.0.1
 license:             BSD3
 license-file:        LICENSE
 copyright:           Copyright (c) 2013-2015 Amgen, Inc.
@@ -92,7 +92,7 @@
                      , th-lift >= 0.6
                      , th-orphans >= 0.8
                      , transformers >= 0.3
-                     , vector >= 0.10 && < 0.12
+                     , vector >= 0.10 && < 0.13
   hs-source-dirs:      src
   includes:            cbits/missing_r.h
   c-sources:           cbits/missing_r.c
diff --git a/src/Foreign/R.chs b/src/Foreign/R.chs
--- a/src/Foreign/R.chs
+++ b/src/Foreign/R.chs
@@ -61,8 +61,10 @@
   , mkWeakRef
     -- * Node attributes
   , typeOf
-  , setAttribute
+  , isS4
+  , setAttributes
   , getAttribute
+  , getAttributes
     -- * Node accessor functions
     -- ** Lists
   , cons
diff --git a/src/Foreign/R/Internal.hsc b/src/Foreign/R/Internal.hsc
--- a/src/Foreign/R/Internal.hsc
+++ b/src/Foreign/R/Internal.hsc
@@ -314,14 +314,28 @@
 -- Attribute header                                                          --
 -------------------------------------------------------------------------------
 
+-- | Check if object is an S4 object.
+--
+-- This is a function call so it will be more precise than using 'typeOf'.
+isS4 :: SEXP s ty -> Bool
+isS4 s = (>0) $ cisS4 (unsexp s)
+
 -- | Get the attribute list from the given object.
-getAttribute :: SEXP s a -> IO (SEXP s b)
-getAttribute s = sexp <$> cATTRIB (unsexp s)
+getAttributes :: SEXP s a -> IO (SEXP s b)
+getAttributes s = sexp <$> cAttrib (unsexp s)
 
--- | Set the attribute list.
-setAttribute :: SEXP s a -> SEXP s b -> IO ()
-setAttribute s v = cSET_ATTRIB (unsexp s) (castPtr $ unsexp v)
+-- | Get attribute with the given name.
+getAttribute :: SEXP s  a -- ^ Value
+             -> SEXP s2 b -- ^ Attribute name
+             -> SEXP s  c
+getAttribute a b = sexp $ cgetAttrib (unsexp a) (unsexp b)
 
-foreign import capi unsafe "Rinternals.h ATTRIB" cATTRIB :: SEXP0 -> IO SEXP0
-foreign import capi unsafe "Rinternals.h SET_ATTRIB" cSET_ATTRIB :: SEXP0 -> SEXP0 -> IO ()
 
+-- | Set the attribute list.
+setAttributes :: SEXP s a -> SEXP s b -> IO ()
+setAttributes s v = csetAttrib (unsexp s) (castPtr $ unsexp v)
+
+foreign import capi unsafe "Rinternals.h ATTRIB" cAttrib :: SEXP0 -> IO SEXP0
+foreign import capi unsafe "Rinternals.h SET_ATTRIB" csetAttrib :: SEXP0 -> SEXP0 -> IO ()
+foreign import capi unsafe "Rinternals.h Rf_getAttrib" cgetAttrib :: SEXP0 -> SEXP0 -> SEXP0
+foreign import capi unsafe "Rinternals.h Rf_isS4" cisS4 :: SEXP0 -> Int
diff --git a/src/Language/R/Debug.hs b/src/Language/R/Debug.hs
--- a/src/Language/R/Debug.hs
+++ b/src/Language/R/Debug.hs
@@ -72,7 +72,7 @@
       nil = R.unsexp H.nilValue
       miss = R.unsexp H.missingArg
       info = unsafePerformIO $ R.peekInfo x
-      attr = unsafePerformIO $ R.getAttribute x
+      attr = unsafePerformIO $ R.getAttributes x
       tp = T.pack . show $ R.infoType info
       go :: SEXP s a -> Value
       go y | R.unsexp y == ub   = A.String "UnboundValue"
diff --git a/src/Language/R/Instance.hs b/src/Language/R/Instance.hs
--- a/src/Language/R/Instance.hs
+++ b/src/Language/R/Instance.hs
@@ -145,7 +145,15 @@
   , configArgs :: [String]
 
     -- | Set to 'True' if you're happy to let R install its own signal handlers
-    -- during initialization.
+    -- during initialization. By default R sets following signal handlers:
+    --
+    --  * SIGPIPE - ignore signal;
+    --  * SIGUSR1 - save workspace and terminate program;
+    --  * SIGUSR2 - terminate program without saving workspace;
+    --  * SIGINT  - cancel execution of the current function.
+    --
+    -- *N.B.* When program is terminated, haskell runtime will not have any chances
+    -- to run any exception handlers or finalizers.
   , configSignalHandlers :: Last Bool
   }