diff --git a/atlassian-connect-core.cabal b/atlassian-connect-core.cabal
--- a/atlassian-connect-core.cabal
+++ b/atlassian-connect-core.cabal
@@ -10,7 +10,7 @@
 -- PVP summary:      +-+------- breaking API changes
 --                   | | +----- non-breaking API additions
 --                   | | | +--- code changes with no API change
-version:             0.4.0.0
+version:             0.5.0.0
 
 -- A short (one-line) description of the package.
 synopsis:            Atlassian Connect snaplet for the Snap Framework and helper code.
diff --git a/src/Snap/AtlassianConnect/HostRequest.hs b/src/Snap/AtlassianConnect/HostRequest.hs
--- a/src/Snap/AtlassianConnect/HostRequest.hs
+++ b/src/Snap/AtlassianConnect/HostRequest.hs
@@ -100,8 +100,8 @@
 hostRequest :: FromJSON a => StdMethod -> AC.Tenant -> B.ByteString -> [(B.ByteString, Maybe B.ByteString)] -> Endo Request -> SS.Handler b AC.Connect (Either ProductErrorResponse a)
 hostRequest standardHttpMethod tenant productRelativeUrl queryParams requestModifications = do
     currentTime <- MI.liftIO P.getPOSIXTime
-    pluginKey <- fmap (CD.pluginKey . AC.connectPlugin) get
-    case generateJWTToken pluginKey currentTime (AC.sharedSecret tenant) standardHttpMethod productBaseUrl url of
+    pluginKey' <- fmap (CD.pluginKey . AC.connectPlugin) get
+    case generateJWTToken pluginKey' currentTime (AC.sharedSecret tenant) standardHttpMethod productBaseUrl url of
         Nothing -> return . Left $ ProductErrorResponse 500 "Failed to generate a JWT token to make the request. The request was never made: server error."
         (Just signature) -> MI.liftIO $ runRequest defaultManagerSettings standardHttpMethod url
             (  addHeader ("Accept","application/json")
@@ -118,9 +118,9 @@
         productBaseUrl = AC.getURI . AC.baseUrl $ tenant
 
 generateJWTToken :: CD.PluginKey -> P.POSIXTime -> T.Text -> StdMethod -> URI -> T.Text -> Maybe T.Text
-generateJWTToken pluginKey fromTime sharedSecret' method' ourURL requestURL = do
+generateJWTToken pluginKey' fromTime sharedSecret' method' ourURL requestURL = do
   queryStringHash <- QSH.createQueryStringHash method' ourURL requestURL
-  return $ JWT.encodeSigned JWT.HS256 (JWT.secret sharedSecret') (createClaims pluginKey fromTime queryStringHash)
+  return $ JWT.encodeSigned JWT.HS256 (JWT.secret sharedSecret') (createClaims pluginKey' fromTime queryStringHash)
 
 createClaims :: CD.PluginKey -> P.POSIXTime -> T.Text -> JWT.JWTClaimsSet
 createClaims (CD.PluginKey pluginKey) fromTime queryStringHash = JWT.JWTClaimsSet
diff --git a/src/Snap/AtlassianConnect/QueryStringHash.hs b/src/Snap/AtlassianConnect/QueryStringHash.hs
--- a/src/Snap/AtlassianConnect/QueryStringHash.hs
+++ b/src/Snap/AtlassianConnect/QueryStringHash.hs
@@ -1,23 +1,24 @@
+{-# LANGUAGE CPP               #-}
 {-# LANGUAGE OverloadedStrings #-}
-{-# LANGUAGE CPP #-}
 module Snap.AtlassianConnect.QueryStringHash
     ( createQueryStringHash
     , module Network.HTTP.Types
     ) where
 
-import qualified Data.Text             as T
-import qualified Data.Text.Encoding    as TE
-import qualified Data.ByteString.Char8 as B
+import           Control.Applicative
+import           Control.Monad         (guard)
 import qualified Crypto.Hash           as SHA
-import           Network.HTTP.Types
-import           Network.URI
+import qualified Data.ByteString.Char8 as B
 import           Data.Function
-import           Data.Ord
+import           Data.List
+import           Data.List.Split
 import           Data.Maybe
 import           Data.Monoid
-import           Data.List.Split
-import           Control.Applicative
-import           Data.List
+import           Data.Ord
+import qualified Data.Text             as T
+import qualified Data.Text.Encoding    as TE
+import           Network.HTTP.Types
+import           Network.URI
 
 
 -- $setup
@@ -37,8 +38,8 @@
 -- :}
 -- Just "70282c7cf82834bd5a3d6dacda1b4ccd5cf5860a63a1fa2fb86b64d576e6a1d5"
 createQueryStringHash :: StdMethod -> URI -> T.Text -> Maybe T.Text
-createQueryStringHash method baseUrl str =
-   (TE.decodeUtf8 . SHA.digestToHexByteString . hsh) <$> toCanonicalUrl method baseUrl str
+createQueryStringHash method baseUrl fullUrl =
+   (TE.decodeUtf8 . SHA.digestToHexByteString . hsh) <$> toCanonicalUrl method baseUrl fullUrl
 
 hsh :: T.Text -> SHA.Digest SHA.SHA256
 hsh = SHA.hash . TE.encodeUtf8
@@ -46,22 +47,25 @@
 -- TODO we ask for the method just so that we can run show method on it...I think we should give it
 -- here in a different way and not mandate StdMethod.
 toCanonicalUrl :: StdMethod -> URI -> T.Text -> Maybe T.Text
-toCanonicalUrl method baseUrl input = do
-   uri <- parseURI (T.unpack input)
-   let path' = stripContextPath baseUrl uri
-   let sqs = sortedQueryString uri
+toCanonicalUrl method baseUrl' rawFullUrl = do
+   fullUrl <- parseURI (T.unpack rawFullUrl)
+   guard (comparing uriScheme baseUrl' fullUrl == EQ)
+   guard (comparing uriAuthority baseUrl' fullUrl == EQ)
+   path' <- uriPath <$> stripBaseUrl baseUrl' fullUrl
+   let sqs = sortedQueryString fullUrl
    return . T.pack $ intercalate "&" [show method, path', sqs]
 
 sortedQueryString :: URI -> String
 sortedQueryString = toCanonicalQueryString . parseQueryText . B.pack . uriQuery
 
-stripContextPath :: URI -> URI -> String
-stripContextPath baseUrl' uri = sep <> intercalate sep (u \\ b)
-   where
-      sep = "/"
-      f = splitOn sep . uriPath
-      b = f baseUrl'
-      u = f uri
+stripBaseUrl :: URI -> URI -> Maybe URI
+stripBaseUrl baseUrl' fullUrl = do
+    strippedPath <- stripPrefix (uriPath baseUrl') (uriPath fullUrl)
+    return fullUrl
+        { uriScheme = ""
+        , uriAuthority = Nothing
+        , uriPath = strippedPath
+        }
 
 {-
  - See step 5 of Creating a Query Hash:
@@ -86,12 +90,12 @@
 ignoreJWTParam :: [(T.Text, a)] -> [(T.Text, a)]
 ignoreJWTParam = filter ((/= "jwt") . fst)
 
-sortParamValues :: Ord b => [(a, b)] -> [(a, b)]
-sortParamValues = sortBy (comparing snd)
-
 sortParamKeys :: Ord a => [(a, b)] -> [(a, b)]
 sortParamKeys = sortBy (comparing fst)
 
+sortParamValues :: Ord b => [(a, b)] -> [(a, b)]
+sortParamValues = sortBy (comparing snd)
+
 groupAndSortQueryParams :: [QueryParam] -> [[QueryParam]]
 groupAndSortQueryParams = fmap sortParamValues . groupBy ((==) `on` fst) . sortParamKeys
 
@@ -111,11 +115,4 @@
 render = T.intercalate "&" . fmap queryParamToString
 
 encode :: T.Text -> T.Text
-encode = T.foldl' encodeChars T.empty
-  where
-    encodeChars :: T.Text -> Char -> T.Text
-    encodeChars s c = case c of
-      ' ' -> s <> "%20"
-      '&' -> s <> "%26"
-      '*' -> s <> "%2A"
-      _   -> s `T.snoc` c
+encode = TE.decodeUtf8 . urlEncode True . TE.encodeUtf8