diff --git a/cmake/QtPublicWasmToolchainHelpers.cmake b/cmake/QtPublicWasmToolchainHelpers.cmake
index 2b93284cda8..ea2a65bade3 100644
--- a/cmake/QtPublicWasmToolchainHelpers.cmake
+++ b/cmake/QtPublicWasmToolchainHelpers.cmake
@@ -98,9 +98,11 @@ function(_qt_test_emscripten_version)
     __qt_internal_get_qt_build_emsdk_version(qt_build_emcc_version)
 
     if(NOT "${qt_build_emcc_version}" STREQUAL "" AND NOT "${qt_build_emcc_version}" STREQUAL "${current_emsdk_ver}")
-        message("Qt Wasm built with Emscripten version: ${qt_build_emcc_version}")
-        message("You are using Emscripten version: ${current_emsdk_ver}")
-        message("The recommended version of Emscripten for this Qt is: ${_recommended_emver}")
-        message("This may not work correctly")
+        message(FATAL_ERROR
+            "Qt Wasm was built with Emscripten version: ${qt_build_emcc_version}\n"
+            "You are using Emscripten version: ${current_emsdk_ver}\n"
+            "The recommended version of Emscripten for this Qt is: ${_recommended_emver}\n"
+            "Stopping configuration due to mismatch of Emscripten versions."
+        )
     endif()
 endfunction()
diff --git a/mkspecs/features/wasm/emcc_ver.prf b/mkspecs/features/wasm/emcc_ver.prf
index 340d4f29e36..b394ea1f518 100644
--- a/mkspecs/features/wasm/emcc_ver.prf
+++ b/mkspecs/features/wasm/emcc_ver.prf
@@ -19,7 +19,7 @@ defineTest(qtConfTest_emccVersion) {
     }
     contains(TEMPLATE, .*app) {
            !equals(QT_EMCC_VERSION, $$EMCC_VERSION)  {
-               warning("This Qt was built with Emscripten version $${QT_EMCC_VERSION}. You have $${EMCC_VERSION}. The difference may cause issues.")
+               error("This Qt was built with Emscripten version $${QT_EMCC_VERSION}. You have $${EMCC_VERSION}. Stopping configuration due to mismatch of Emscripten versions.")
            }
     }
 }