diff --git a/CMakeLists.txt b/CMakeLists.txt
index 0c4079ce..445688cc 100644
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -382,6 +382,7 @@ else()
     target_link_options( ${EXECUTABLE_NAME} PRIVATE "-sEXPORTED_RUNTIME_METHODS=callMain,addRunDependency,removeRunDependency" )
     target_link_options( ${EXECUTABLE_NAME} PRIVATE "-sEXPORT_ALL" )
     target_link_options( ${EXECUTABLE_NAME} PRIVATE "-sEXPORT_NAME=fallout2ce" )
+    target_link_options( ${EXECUTABLE_NAME} PRIVATE "-gsource-map" )
 endif()
 
 target_link_libraries(${EXECUTABLE_NAME} ${ZLIB_LIBRARIES})
diff --git a/cmake/toolchain/Emscripten.cmake b/cmake/toolchain/Emscripten.cmake
index fa1a010c..8e023c50 100644
--- a/cmake/toolchain/Emscripten.cmake
+++ b/cmake/toolchain/Emscripten.cmake
@@ -4,8 +4,10 @@ set( CMAKE_C_COMPILER                   "emcc" )
 set( CMAKE_CXX_COMPILER                 "em++" )
 set( CMAKE_C_FLAGS                      "--use-port=sdl2 \
                                         --use-port=sdl2_mixer \
-                                        --use-port=zlib" )
+                                        --use-port=zlib \
+                                        -gsource-map" )
 set( CMAKE_CXX_FLAGS                    "--use-port=sdl2 \
                                         --use-port=sdl2_mixer \
-                                        --use-port=zlib" )
+                                        --use-port=zlib \
+                                        -gsource-map" )
 set( EXECUTABLE_NAME fallout2-ce.js )
\ No newline at end of file
diff --git a/src/xfile.cc b/src/xfile.cc
index d917c217..f47d1d26 100644
--- a/src/xfile.cc
+++ b/src/xfile.cc
@@ -68,12 +68,10 @@ int xfileClose(XFile* stream)
             EM_ASM(
                 // clang-format off
                 // The following code is not C++ code, but JavaScript code.
-                const handle = setInterval(() => {
-                    if (FS.syncFSRequests === 0) {
-                        clearInterval(handle);
-                        FS.syncfs(err => err && console.warn(`FS.syncfs() error: ${err}`, err));
-                    }
-                }, 0);
+                setTimeout(() => {
+                    if (FS.syncFSRequests !== 0) return;
+                    FS.syncfs(err => err && console.warn(`FS.syncfs() error: ${err}`, err));
+                }, 0)
                 // clang-format on
             );
         }