diff --git a/dist-build/emscripten.sh b/dist-build/emscripten.sh
index af6e7c8c..35028e45 100755
--- a/dist-build/emscripten.sh
+++ b/dist-build/emscripten.sh
@@ -42,6 +42,7 @@ elif [ "x$1" = "x--browser-tests" ]; then
 elif [ "x$1" = "x--tests" ]; then
   echo "Building for testing"
   export EXPORTED_FUNCTIONS="$EXPORTED_FUNCTIONS_SUMO"
+  export CPPFLAGS="${CPPFLAGS} -DBENCHMARKS -DITERATIONS=10"
   export LDFLAGS="${LDFLAGS} -s TOTAL_MEMORY=${TOTAL_MEMORY_TESTS}"
   export PREFIX="$(pwd)/libsodium-js-tests"
   export DONE_FILE="$(pwd)/js-tests.done"
diff --git a/test/default/cmptest.h b/test/default/cmptest.h
index bcf1064b..1a46d41b 100644
--- a/test/default/cmptest.h
+++ b/test/default/cmptest.h
@@ -137,6 +137,10 @@ int main(void)
     if (sodium_init() != 0) {
         return 99;
     }
+#ifdef __EMSCRIPTEN__
+    (void) fopen("/dev/null", "r");
+#endif
+
 #ifndef __EMSCRIPTEN__
     randombytes_set_implementation(&randombytes_salsa20_implementation);
 #endif