diff --git a/hspec/Hasql/PipelineSpec.hs b/hspec/Hasql/PipelineSpec.hs
index 7b88c23..57fc226 100644
--- a/hspec/Hasql/PipelineSpec.hs
+++ b/hspec/Hasql/PipelineSpec.hs
@@ -57,12 +57,13 @@ spec = do
         it "Leaves the connection usable" do
           result <-
             Dsl.runSessionOnLocalDb do
-              tryError
-                $ Dsl.runPipelineInSession
-                $ (,,)
-                <$> GenerateSeries.pipeline True GenerateSeries.Params {start = 0, end = 2}
-                <*> BrokenSyntax.pipeline True BrokenSyntax.Params {start = 0, end = 2}
-                <*> GenerateSeries.pipeline True GenerateSeries.Params {start = 0, end = 2}
+              _ <-
+                tryError
+                  $ Dsl.runPipelineInSession
+                  $ (,,)
+                  <$> GenerateSeries.pipeline True GenerateSeries.Params {start = 0, end = 2}
+                  <*> BrokenSyntax.pipeline True BrokenSyntax.Params {start = 0, end = 2}
+                  <*> GenerateSeries.pipeline True GenerateSeries.Params {start = 0, end = 2}
               GenerateSeries.session True GenerateSeries.Params {start = 0, end = 0}
           shouldBe result (Right [0])
 
@@ -81,11 +82,12 @@ spec = do
         it "Leaves the connection usable" do
           result <-
             Dsl.runSessionOnLocalDb do
-              tryError
-                $ Dsl.runPipelineInSession
-                $ (,,)
-                <$> GenerateSeries.pipeline True GenerateSeries.Params {start = 0, end = 2}
-                <*> WrongDecoder.pipeline True WrongDecoder.Params {start = 0, end = 2}
-                <*> GenerateSeries.pipeline True GenerateSeries.Params {start = 0, end = 2}
+              _ <-
+                tryError
+                  $ Dsl.runPipelineInSession
+                  $ (,,)
+                  <$> GenerateSeries.pipeline True GenerateSeries.Params {start = 0, end = 2}
+                  <*> WrongDecoder.pipeline True WrongDecoder.Params {start = 0, end = 2}
+                  <*> GenerateSeries.pipeline True GenerateSeries.Params {start = 0, end = 2}
               GenerateSeries.session True GenerateSeries.Params {start = 0, end = 0}
           shouldBe result (Right [0])
diff --git a/library/Hasql/Session/Core.hs b/library/Hasql/Session/Core.hs
index f544632..c54a027 100644
--- a/library/Hasql/Session/Core.hs
+++ b/library/Hasql/Session/Core.hs
@@ -46,7 +46,7 @@ sql :: ByteString -> Session ()
 sql sql =
   Session
     $ ReaderT
-    $ \(Connection.Connection pqConnectionRef integerDatetimes registry) ->
+    $ \(Connection.Connection pqConnectionRef integerDatetimes _) ->
       ExceptT
         $ fmap (first (QueryError sql []))
         $ withMVar pqConnectionRef
diff --git a/profiling/Main.hs b/profiling/Main.hs
index 35180e4..dbe5410 100644
--- a/profiling/Main.hs
+++ b/profiling/Main.hs
@@ -12,7 +12,7 @@ main =
   do
     Right connection <- acquireConnection
     traceEventIO "START Session"
-    Right result <- B.run sessionWithManySmallResults connection
+    Right _ <- B.run sessionWithManySmallResults connection
     traceEventIO "STOP Session"
     return ()
   where
diff --git a/tasty/Main.hs b/tasty/Main.hs
index 9c4802a..361c85f 100644
--- a/tasty/Main.hs
+++ b/tasty/Main.hs
@@ -279,7 +279,7 @@ tree =
                   Session.sql "asldfjsldk"
                 io =
                   Connection.with $ \c -> do
-                    Session.run errorSession c
+                    _ <- Session.run errorSession c
                     Session.run sumSession c
              in io >>= \x -> assertBool (show x) (either (const False) isRight x),
         testCase "\"another command is already in progress\" bugfix"