diff --git a/CMakeModules/DownloadExternals.cmake b/CMakeModules/DownloadExternals.cmake
index e75829d4e..47070cae6 100644
--- a/CMakeModules/DownloadExternals.cmake
+++ b/CMakeModules/DownloadExternals.cmake
@@ -41,9 +41,12 @@ endfunction()
 function(download_moltenvk_external platform version)
     set(MOLTENVK_DIR "${CMAKE_BINARY_DIR}/externals/MoltenVK")
     set(MOLTENVK_TAR "${CMAKE_BINARY_DIR}/externals/MoltenVK.tar")
+    # MoltenVK release asset filenames use lowercase platform names (e.g., 'macos', 'ios'),
+    # but the extracted directory structure uses mixed case (e.g., 'macOS', 'iOS').
+    string(TOLOWER "${platform}" MOLTENVK_ASSET_PLATFORM)
     if (NOT EXISTS ${MOLTENVK_DIR})
         if (NOT EXISTS ${MOLTENVK_TAR})
-            file(DOWNLOAD https://github.com/KhronosGroup/MoltenVK/releases/download/${version}/MoltenVK-${platform}.tar
+            file(DOWNLOAD https://github.com/KhronosGroup/MoltenVK/releases/download/${version}/MoltenVK-${MOLTENVK_ASSET_PLATFORM}.tar
                 ${MOLTENVK_TAR} SHOW_PROGRESS)
         endif()
 
diff --git a/src/citron/CMakeLists.txt b/src/citron/CMakeLists.txt
index 0b5bec7e9..a5bc98957 100644
--- a/src/citron/CMakeLists.txt
+++ b/src/citron/CMakeLists.txt
@@ -364,7 +364,7 @@ if (APPLE)
 
     if (NOT USE_SYSTEM_MOLTENVK)
         set(MOLTENVK_PLATFORM "macOS")
-        set(MOLTENVK_VERSION "v1.2.7")
+        set(MOLTENVK_VERSION "v1.4.0-rc1")
         download_moltenvk_external(${MOLTENVK_PLATFORM} ${MOLTENVK_VERSION})
     endif()
     find_library(MOLTENVK_LIBRARY MoltenVK REQUIRED)