diff --git a/test/test_subprocess.cc b/test/test_subprocess.cc
new file mode 100755
index 0000000..dcffb27
--- /dev/null
+++ b/test/test_subprocess.cc
@@ -0,0 +1,20 @@
+#include <iostream>
+#include "../subprocess.hpp"
+
+using namespace subprocess;
+
+void test_input()
+{
+  auto p = Popen({"grep", "f"}, output{PIPE}, input{PIPE});
+  const char* msg = "one\ntwo\nfour\n";
+  std::fwrite(msg, 1, strlen(msg), p.input());
+  fclose (p.input());
+
+  std::vector<uint8_t> rbuf(128);
+  std::fread(rbuf.data(), 1, 128, p.output());
+}
+
+int main() {
+  test_input();
+  return 0;
+}