diff --git a/test/run-wasi-test.py b/test/run-wasi-test.py
index d642499..d5d3a9f 100755
--- a/test/run-wasi-test.py
+++ b/test/run-wasi-test.py
@@ -4,7 +4,7 @@
 # Usage:
 #   ./run-wasi-test.py
 #   ./run-wasi-test.py --exec ../custom_build/wasm3 --timeout 120
-#   ./run-wasi-test.py --exec "wasmer run"
+#   ./run-wasi-test.py --exec "wasmer run --dir=."
 #
 
 import argparse
@@ -63,13 +63,13 @@ commands = [
   {
     "name":           "Simple WASI test",
     "wasm":           "./wasi/test.wasm",
-    "args":           ["args", "test"],
-    "expect_pattern": "Hello world*Constructor OK*Args: *; args; test;*fib(20) = 6765*[* ms]*=== done ===*"
+    "args":           ["cat", "./wasi/0.txt"],
+    "expect_pattern": "Hello world*Constructor OK*Args: *; cat; ./wasi/0.txt;*fib(20) = 6765*[* ms]*48 65 6c 6c 6f 20 77 6f 72 6c 64*=== done ===*"
   }, {
     "name":           "Simple WASI test (wasm-opt -O3)",
     "wasm":           "./wasi/test-opt.wasm",
-    "args":           ["args", "test"],
-    "expect_pattern": "Hello world*Constructor OK*Args: *; args; test;*fib(20) = 6765*[* ms]*=== done ===*"
+    "args":           ["cat", "./wasi/0.txt"],
+    "expect_pattern": "Hello world*Constructor OK*Args: *; cat; ./wasi/0.txt;*fib(20) = 6765*[* ms]*48 65 6c 6c 6f 20 77 6f 72 6c 64*=== done ===*"
   }, {
     "name":           "mandelbrot",
     "wasm":           "./benchmark/mandelbrot/mandel.wasm",
@@ -97,6 +97,7 @@ commands = [
     "wasm":           "./benchmark/stream/stream.wasm",
     "expect_pattern": "----*Solution Validates:*on all three arrays*----*"
   }, {
+    # TODO "if":             { "file_exists": "./self-hosting/wasm3-fib.wasm" },
     "name":           "Self-hosting",
     "wasm":           "./self-hosting/wasm3-fib.wasm",
     "expect_pattern": "wasm3 on WASM*Result: 832040*Elapsed: * ms*"
diff --git a/test/wasi/test-opt.wasm b/test/wasi/test-opt.wasm
index 443a9a0..db11c80 100644
Binary files a/test/wasi/test-opt.wasm and b/test/wasi/test-opt.wasm differ
diff --git a/test/wasi/test.c b/test/wasi/test.c
index 0ca6b34..8e72c2f 100644
--- a/test/wasi/test.c
+++ b/test/wasi/test.c
@@ -3,6 +3,9 @@
 #include <string.h>
 #include <time.h>
 
+#include <sys/stat.h>
+#include <fcntl.h>
+
 /*
  * Helpers
  */
@@ -105,6 +108,20 @@ void test_perf_fib(uint32_t n) {
   printf("%d [%.3f ms]\n", result, fms);
 }
 
+void test_cat(char* fn) {
+  int file = open(fn, O_RDONLY);
+  if (file >= 0) {
+    char c = 0;
+    while (read(file, &c, sizeof(c)) > 0) {
+      printf("%02x ", c);
+    }
+    close(file);
+    puts("");
+  } else {
+    printf("Cannot open %s\n", fn);
+  }
+}
+
 /*
  * Main
  */
@@ -116,9 +133,13 @@ int main(int argc, char **argv)
   test_printf();
   test_args(argc, argv);
   test_gettime();
-  test_random();
+  //test_random();
   test_perf_fib(20);
 
+  if (0 == strcmp(argv[1], "cat")) {
+    test_cat(argv[2]);
+  }
+
   puts("=== done ===");
   return 0;
 }
diff --git a/test/wasi/test.wasm b/test/wasi/test.wasm
index a299332..e516740 100755
Binary files a/test/wasi/test.wasm and b/test/wasi/test.wasm differ