diff --git a/Aws/Iam/Core.hs b/Aws/Iam/Core.hs
--- a/Aws/Iam/Core.hs
+++ b/Aws/Iam/Core.hs
@@ -133,9 +133,8 @@
                           , ("SignatureMethod" , Just $ amzHash HmacSHA256)
                           , ("SignatureVersion", Just "2")
                           , ("Version"         , Just "2010-05-08")
-                          , timestampHeader
-			  , ("SecurityToken", iamToken signatureCredentials)
-                          ]
+                          , timestampHeader] ++
+                          maybe [] (\tok -> [ ("SecurityToken", Just tok)]) (iamToken signatureCredentials)
 
 -- | Reads the metadata from an IAM response and delegates parsing the rest of
 -- the data from the response to the given function.
diff --git a/Aws/Sqs/Core.hs b/Aws/Sqs/Core.hs
--- a/Aws/Sqs/Core.hs
+++ b/Aws/Sqs/Core.hs
@@ -188,8 +188,8 @@
       expandedQuery = sortBy (comparing fst) 
                        ( sqsQuery ++ [ ("AWSAccessKeyId", Just(accessKeyID signatureCredentials)), 
                        ("Expires", Just(BC.pack expiresString)), 
-                       ("SignatureMethod", Just("HmacSHA256")), ("SignatureVersion",Just("2")), ("Version",Just("2012-11-05")),
-                       ("SecurityToken", iamToken signatureCredentials)])
+                       ("SignatureMethod", Just("HmacSHA256")), ("SignatureVersion",Just("2")), ("Version",Just("2012-11-05"))] ++
+                       maybe [] (\tok -> [("SecurityToken", Just tok)]) (iamToken signatureCredentials))
 
       expires = AbsoluteExpires $ sqsDefaultExpiry `addUTCTime` signatureTime
 
@@ -204,7 +204,7 @@
 
       signedQuery = expandedQuery ++ (HTTP.simpleQueryToQuery $ makeAuthQuery)
 
-      makeAuthQuery = [("Signature", sig)] ++ maybe [] (\x -> [("x-amz-security-token", x)]) (iamToken signatureCredentials)
+      makeAuthQuery = [("Signature", sig)]
 
 sqsResponseConsumer :: HTTPResponseConsumer a
                     -> IORef SqsMetadata
diff --git a/README.org b/README.org
--- a/README.org
+++ b/README.org
@@ -90,6 +90,9 @@
 
 ** 0.10 series
 
+- 0.10.3
+  - fix bug introduced in 0.10.2 that broke SQS and IAM connections without STS
+
 - 0.10.2
   - support STS / IAM temporary credentials in all services
 
diff --git a/aws.cabal b/aws.cabal
--- a/aws.cabal
+++ b/aws.cabal
@@ -1,5 +1,5 @@
 Name:                aws
-Version:             0.10.2
+Version:             0.10.3
 Synopsis:            Amazon Web Services (AWS) for Haskell
 Description:         Bindings for Amazon Web Services (AWS), with the aim of supporting all AWS services. To see a high level overview of the library, see the README at <https://github.com/aristidb/aws/blob/master/README.org>.
 Homepage:            http://github.com/aristidb/aws
@@ -20,7 +20,7 @@
 Source-repository this
   type: git
   location: https://github.com/aristidb/aws.git
-  tag: 0.10.2
+  tag: 0.10.3
 
 Source-repository head
   type: git