diff --git a/src/CMakeLists.txt b/src/CMakeLists.txt
index 7000a07..fbbb71c 100644
--- a/src/CMakeLists.txt
+++ b/src/CMakeLists.txt
@@ -46,7 +46,7 @@ fips_end_app()
 target_compile_definitions(v6502r PRIVATE CHIP_6502)
 target_include_directories(v6502r PRIVATE m6502)
 if (FIPS_EMSCRIPTEN)
-    target_link_options(v6502r PUBLIC --shell-file ${CMAKE_SOURCE_DIR}/src/m6502/shell.html -sLEGACY_RUNTIME=1)
+    target_link_options(v6502r PUBLIC --shell-file ${CMAKE_SOURCE_DIR}/src/m6502/shell.html)
 endif()
 
 fips_begin_app(vz80r windowed)
@@ -59,7 +59,7 @@ fips_end_app()
 target_compile_definitions(vz80r PRIVATE CHIP_Z80)
 target_include_directories(vz80r PRIVATE z80)
 if (FIPS_EMSCRIPTEN)
-    target_link_options(vz80r PUBLIC --shell-file ${CMAKE_SOURCE_DIR}/src/z80/shell.html -sLEGACY_RUNTIME=1)
+    target_link_options(vz80r PUBLIC --shell-file ${CMAKE_SOURCE_DIR}/src/z80/shell.html)
 endif()
 
 fips_begin_app(v2a03r windowed)
@@ -72,5 +72,5 @@ fips_end_app()
 target_compile_definitions(v2a03r PRIVATE CHIP_2A03)
 target_include_directories(v2a03r PRIVATE 2a03)
 if (FIPS_EMSCRIPTEN)
-    target_link_options(v2a03r PUBLIC --shell-file ${CMAKE_SOURCE_DIR}/src/2a03/shell.html -sLEGACY_RUNTIME=1)
+    target_link_options(v2a03r PUBLIC --shell-file ${CMAKE_SOURCE_DIR}/src/2a03/shell.html)
 endif()
diff --git a/src/util.c b/src/util.c
index ca598c1..6b86004 100644
--- a/src/util.c
+++ b/src/util.c
@@ -12,6 +12,8 @@ static struct {
 } util;
 
 #if defined(__EMSCRIPTEN__)
+EM_JS_DEPS(v6502r, "$ccall");
+
 EM_JS(void, emsc_js_init, (void), {
     Module['emsc_js_onload'] = emsc_js_onload;
 });