diff --git a/.github/workflows/tests.yml b/.github/workflows/tests.yml
index cd279a2..002fbcc 100644
--- a/.github/workflows/tests.yml
+++ b/.github/workflows/tests.yml
@@ -114,7 +114,7 @@ jobs:
         source $HOME/.wasienv/wasienv.sh
         mkdir build-wasi
         cd build-wasi
-        wasimake cmake -DWASIENV=1 ..
+        wasimake cmake ..
     - name: Build
       run: |
         source $HOME/.wasienv/wasienv.sh
diff --git a/CMakeLists.txt b/CMakeLists.txt
index b4692cb..2eb7356 100755
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -1,5 +1,7 @@
 cmake_minimum_required(VERSION 3.9)
 
+option(BUILD_WASI_SUPPORT "Build with WASI support" ON)
+
 set(OUT_FILE "wasm3")
 set(APP_DIR  "platforms/app")
 
@@ -36,6 +38,11 @@ if(EMSCRIPTEN)
   set(APP_DIR            "platforms/emscripten")
 endif()
 
+# Detect WasiEnv
+if(DEFINED ENV{WASI_CC})
+  set(WASIENV            1)
+endif()
+
 if(BUILD_32BIT)
   set(CMAKE_C_FLAGS   "${CMAKE_C_FLAGS}   -m32")
 endif()
@@ -77,7 +84,10 @@ if(EMSCRIPTEN)
     set(CMAKE_C_FLAGS_RELEASE "${CMAKE_C_FLAGS_RELEASE} -Xclang -target-feature -Xclang +tail-call")
   endif()
 elseif(WASIENV)
-  set(CMAKE_C_FLAGS "${CMAKE_C_FLAGS} -Dd_m3HasMetaWASI")
+
+  if(BUILD_WASI_SUPPORT)
+    set(CMAKE_C_FLAGS "${CMAKE_C_FLAGS} -Dd_m3HasMetaWASI")
+  endif()
 
   set(CMAKE_C_FLAGS_RELEASE "-O3 -Wfatal-errors -fomit-frame-pointer -fno-stack-check -fno-stack-protector")
 
@@ -87,7 +97,10 @@ elseif(WASIENV)
   #-flto -Wl,--lto-O3
   set(CMAKE_EXE_LINKER_FLAGS      "${CMAKE_EXE_LINKER_FLAGS} -Wl,-z,stack-size=8388608")
 elseif(WIN32)
-  set(CMAKE_C_FLAGS "${CMAKE_C_FLAGS} -Dd_m3HasWASI")
+
+  if(BUILD_WASI_SUPPORT)
+    set(CMAKE_C_FLAGS "${CMAKE_C_FLAGS} -Dd_m3HasWASI")
+  endif()
 
   set(CMAKE_C_FLAGS "${CMAKE_C_FLAGS} -D_CRT_SECURE_NO_WARNINGS /WX- /diagnostics:column")
 
@@ -107,7 +120,10 @@ elseif(WIN32)
   set(CMAKE_EXE_LINKER_FLAGS "${CMAKE_EXE_LINKER_FLAGS} /STACK:8388608") # stack size
 
 else()
-  set(CMAKE_C_FLAGS "${CMAKE_C_FLAGS} -Dd_m3HasWASI")
+
+  if(BUILD_WASI_SUPPORT)
+    set(CMAKE_C_FLAGS "${CMAKE_C_FLAGS} -Dd_m3HasWASI") #-Dd_m3FixedHeap=1048576
+  endif()
 
   set(CMAKE_C_FLAGS "${CMAKE_C_FLAGS} -Wall -Wextra -Wparentheses -Wundef -Wpointer-arith -Wstrict-aliasing=2")
   set(CMAKE_C_FLAGS "${CMAKE_C_FLAGS} -Werror=shadow -Werror=implicit-function-declaration") # -Werror=cast-align
diff --git a/platforms/app/main.c b/platforms/app/main.c
index 33125da..8848883 100644
--- a/platforms/app/main.c
+++ b/platforms/app/main.c
@@ -260,8 +260,10 @@ int  main  (int i_argc, const char* i_argv[])
         result = repl_load(runtime, argFile);
         if (result) FATAL("repl_load: %s", result);
 
+#if defined(d_m3HasWASI)
         result = m3_LinkWASI (runtime->modules);
         if (result) FATAL("m3_LinkWASI: %s", result);
+#endif
 
         result = m3_LinkLibC (runtime->modules);
         if (result) FATAL("m3_LinkLibC: %s", result);