diff --git a/subprocess.hpp b/subprocess.hpp
index 668e3ad..bdd3c3b 100755
--- a/subprocess.hpp
+++ b/subprocess.hpp
@@ -306,9 +306,8 @@ namespace util
    *
    * NOTE: `class Buffer` is a exposed public class. See below.
    */
-  template <typename Buffer>
-  // Requires Buffer to be of type class Buffer
-  static inline int read_all(int fd, Buffer& buf)
+
+  static inline int read_all(int fd, std::vector<char>& buf)
   {
     auto buffer = buf.data();
     int total_bytes_read = 0;
@@ -329,8 +328,8 @@ namespace util
 
         //update the buffer pointer
         buffer = buf.data();
-        buffer += rd_bytes;
         total_bytes_read += rd_bytes;
+        buffer += total_bytes_read;
 
       } else { // Partial data ? Continue reading
         total_bytes_read += rd_bytes;
@@ -338,6 +337,7 @@ namespace util
         break;
       }
     }
+    buf.erase(buf.begin()+total_bytes_read, buf.end()); // remove extra nulls
     return total_bytes_read;
   }
 
diff --git a/test/test_subprocess.cc b/test/test_subprocess.cc
index d02aeb8..bf0a694 100755
--- a/test/test_subprocess.cc
+++ b/test/test_subprocess.cc
@@ -51,6 +51,19 @@ void test_sleep()
   std::cout << "Sleep ended: ret code = " << p.retcode() << std::endl;
 }
 
+void test_read_all()
+{
+  Popen p = Popen({"echo","12345678"}, output{PIPE});
+  
+  std::vector<char> buf(6);
+  int rbytes = util::read_all(fileno(p.output()), buf);
+
+  std::string out(buf.begin(), buf.end());
+
+  assert(out == "12345678\n" && rbytes == 9); // echo puts a new line at the end of output
+  std::cout<<"read_all() succeeded"<<std::endl;
+}
+
 int main() {
   test_exename();
   test_input();
@@ -58,5 +71,6 @@ int main() {
   test_easy_piping();
   test_shell();
   test_sleep();
+  test_read_all();
   return 0;
 }