diff --git a/ports/rxcpp/CONTROL b/ports/rxcpp/CONTROL
index 02b8738166b..bf4c3cae8d6 100644
--- a/ports/rxcpp/CONTROL
+++ b/ports/rxcpp/CONTROL
@@ -1,3 +1,3 @@
 Source: rxcpp
-Version: 3.0.0
+Version: 4.0.0
 Description: Reactive Extensions for C++
\ No newline at end of file
diff --git a/ports/rxcpp/portfile.cmake b/ports/rxcpp/portfile.cmake
index 4a321222d89..888c05a2c20 100644
--- a/ports/rxcpp/portfile.cmake
+++ b/ports/rxcpp/portfile.cmake
@@ -1,10 +1,10 @@
 #header-only library
 include(vcpkg_common_functions)
-set(SOURCE_PATH ${CURRENT_BUILDTREES_DIR}/src/RxCpp-3.0.0)
+set(SOURCE_PATH ${CURRENT_BUILDTREES_DIR}/src/RxCpp-4.0.0)
 vcpkg_download_distfile(ARCHIVE
-    URLS "https://github.com/Reactive-Extensions/RxCpp/archive/v3.0.0.tar.gz"
-    FILENAME "RxCpp-v3.0.0.tar.gz"
-    SHA512 6d810b6163d0920d531f32a13729e290c81b47d5fc9c3e3d3d8a25d27a6f0671fec097d091bef7383b7e556e9e5471db087bb955e7f4fd9a5fdc9e7b06050844
+    URLS "https://github.com/Reactive-Extensions/RxCpp/archive/v4.0.0.tar.gz"
+    FILENAME "RxCpp-v4.0.0.tar.gz"
+    SHA512 df7582925e749fb7f9fbc085566d57a46571e18202aacaa7d35cf9da8152b29dd2886b2d07dae93e538f2a0f7b91d93fb3da23c34c7ea4467772515c794a25b7
 )
 vcpkg_extract_source_archive(${ARCHIVE})