diff --git a/ChangeLog.md b/ChangeLog.md
--- a/ChangeLog.md
+++ b/ChangeLog.md
@@ -1,5 +1,9 @@
 # Revision history for lsp-test
 
+## 0.5.1.0 -- 2019-04-22
+
+* Fix unhandled `window/progress` server notifications
+
 ## 0.5.1.0 -- 2019-04-07
 
 * Add getTypeDefinitions (@fendor) 
diff --git a/lsp-test.cabal b/lsp-test.cabal
--- a/lsp-test.cabal
+++ b/lsp-test.cabal
@@ -1,5 +1,5 @@
 name:                lsp-test
-version:             0.5.1.2
+version:             0.5.1.3
 synopsis:            Functional test framework for LSP servers.
 description:
   A test framework for writing tests against
diff --git a/src/Language/Haskell/LSP/Test/Decoding.hs b/src/Language/Haskell/LSP/Test/Decoding.hs
--- a/src/Language/Haskell/LSP/Test/Decoding.hs
+++ b/src/Language/Haskell/LSP/Test/Decoding.hs
@@ -131,6 +131,10 @@
         WindowShowMessage              -> NotShowMessage $ fromJust $ decode bytes
         WindowLogMessage               -> NotLogMessage $ fromJust $ decode bytes
         CancelRequestServer            -> NotCancelRequestFromServer $ fromJust $ decode bytes
+        WindowProgressStart            -> NotProgressStart $ fromJust $ decode bytes
+        WindowProgressReport           -> NotProgressReport $ fromJust $ decode bytes
+        WindowProgressDone             -> NotProgressDone $ fromJust $ decode bytes
+        WindowProgressCancel           -> NotProgressCancel $ fromJust $ decode bytes
         TelemetryEvent                 -> NotTelemetry $ fromJust $ decode bytes
         WindowShowMessageRequest       -> ReqShowMessage $ fromJust $ decode bytes
         ClientRegisterCapability       -> ReqRegisterCapability $ fromJust $ decode bytes
diff --git a/src/Language/Haskell/LSP/Test/Messages.hs b/src/Language/Haskell/LSP/Test/Messages.hs
--- a/src/Language/Haskell/LSP/Test/Messages.hs
+++ b/src/Language/Haskell/LSP/Test/Messages.hs
@@ -90,6 +90,10 @@
     (NotPublishDiagnostics       m) -> notification m
     (NotLogMessage               m) -> notification m
     (NotShowMessage              m) -> notification m
+    (NotProgressStart            m) -> notification m
+    (NotProgressReport           m) -> notification m
+    (NotProgressDone             m) -> notification m
+    (NotProgressCancel           m) -> notification m
     (NotTelemetry                m) -> notification m
     (NotCancelRequestFromServer  m) -> notification m