diff --git a/.travis.yml b/.travis.yml
new file mode 100644
index 0000000..4f98d23
--- /dev/null
+++ b/.travis.yml
@@ -0,0 +1,31 @@
+matrix:
+  include:
+    - os: linux
+      dist: bionic
+      language: cpp
+      compiler: gcc
+    - os: osx
+      osx_image: xcode10.2
+      language: cpp
+      compiler: clang
+    - os: windows
+      language: bash
+      env: CXX=cl.exe
+install:
+  - |
+    if [[ $TRAVIS_OS_NAME == 'windows' ]]; then
+      choco install ninja cmake
+    elif [[ $TRAVIS_OS_NAME == 'osx' ]]; then
+      export PATH=~/Library/Python/3.7/bin:$PATH
+      pip3 install --user ninja cmake
+    else
+      pip install --user ninja cmake
+    fi
+script:
+  - |
+    if [[ $TRAVIS_OS_NAME == 'windows' ]]; then
+      cmd.exe /C '"C:\Program Files (x86)\Microsoft Visual Studio\2017\BuildTools\VC\Auxiliary\Build\vcvarsall.bat" amd64 && cmake -Bbuild -G Ninja -DCMAKE_BUILD_TYPE=Release -DARGPARSE_BUILD_TESTS=ON && ninja -C build'
+    else
+      cmake -Bbuild -G Ninja -DCMAKE_BUILD_TYPE=Release -DARGPARSE_BUILD_TESTS=ON && ninja -C build
+    fi
+  - ./build/test/tests
diff --git a/README.md b/README.md
index aa794a1..01739e2 100644
--- a/README.md
+++ b/README.md
@@ -2,6 +2,14 @@
   <img height="100" src="https://i.imgur.com/oDXeMUQ.png" alt="pprint"/>
 </p>
 
+<p align="center">
+  <img src="https://travis-ci.org/p-ranav/argparse.svg?branch=master" alt="travis"/>
+  <a href="https://github.com/p-ranav/argparse/blob/master/LICENSE">
+    <img src="https://img.shields.io/badge/License-MIT-yellow.svg" alt="license"/>
+  </a>
+  <img src="https://img.shields.io/badge/version-1.8-blue.svg?cacheSeconds=2592000" alt="version"/>
+</p>
+
 ## Highlights
 
 * Single header file
diff --git a/include/argparse.hpp b/include/argparse.hpp
index 7411918..74904cc 100644
--- a/include/argparse.hpp
+++ b/include/argparse.hpp
@@ -102,6 +102,11 @@ public:
     return *this;
   }
 
+  Argument& required() {
+    mIsRequired = true;
+    return *this;
+  }
+
   Argument& implicit_value(std::any aImplicitValue) {
     mImplicitValue = std::move(aImplicitValue);
     mNumArgs = 0;
@@ -152,19 +157,29 @@ public:
     if (mIsOptional) {
       if (mIsUsed && mValues.size() != mNumArgs && !mDefaultValue.has_value()) {
         std::stringstream stream;
-        stream << "error: " << mUsedName << ": expected " << mNumArgs << " argument(s). "
-               << mValues.size() << " provided.\n" << std::endl;
+		stream << "error: " << mUsedName << ": expected " << mNumArgs << " argument(s). "
+			<< mValues.size() << " provided.";
         throw std::runtime_error(stream.str());
       }
       else {
         // TODO: check if an implicit value was programmed for this argument
+        if (!mIsUsed && !mDefaultValue.has_value() && mIsRequired) {
+          std::stringstream stream;
+          stream << "error: " << mNames[0] << ": required.";
+          throw std::runtime_error(stream.str());
+        }
+        if (mIsUsed && mIsRequired && mValues.size() == 0) {
+          std::stringstream stream;
+          stream << "error: " << mUsedName << ": no value provided.";
+          throw std::runtime_error(stream.str());
+        }
       }
     }
     else {
       if (mValues.size() != mNumArgs && !mDefaultValue.has_value()) {
         std::stringstream stream;
-        stream << "error: " << mUsedName << ": expected " << mNumArgs << " argument(s). "
-               << mValues.size() << " provided.\n" << std::endl;
+		stream << "error: " << mUsedName << ": expected " << mNumArgs << " argument(s). "
+			<< mValues.size() << " provided.";
         throw std::runtime_error(stream.str());
       }
     }
@@ -179,7 +194,11 @@ public:
   friend std::ostream& operator<<(std::ostream& stream, const Argument& argument) {
     std::stringstream nameStream;
     std::copy(std::begin(argument.mNames), std::end(argument.mNames), std::ostream_iterator<std::string>(nameStream, " "));
-    return stream << nameStream.str() << "\t" << argument.mHelp << "\n";
+	stream << nameStream.str() << "\t" << argument.mHelp;
+    if (argument.mIsRequired)
+      stream << "[Required]";
+    stream << "\n";
+    return stream;
   }
 
 
@@ -298,6 +317,7 @@ public:
     std::vector<std::string> mRawValues;
     size_t mNumArgs = 1;
     bool mIsOptional = false;
+    bool mIsRequired = false;
     bool mIsUsed = false; // relevant for optional arguments. True if used by user
 
   public:
diff --git a/test/main.cpp b/test/main.cpp
index 2885d40..8d9aa37 100644
--- a/test/main.cpp
+++ b/test/main.cpp
@@ -10,3 +10,4 @@
 #include <test_parent_parsers.hpp>
 #include <test_invalid_arguments.hpp>
 #include <test_negative_numbers.hpp>
+#include <test_required_arguments.hpp>
\ No newline at end of file
diff --git a/test/test_required_arguments.hpp b/test/test_required_arguments.hpp
new file mode 100644
index 0000000..f9ac26e
--- /dev/null
+++ b/test/test_required_arguments.hpp
@@ -0,0 +1,45 @@
+#pragma once
+#include <catch.hpp>
+#include <argparse.hpp>
+
+TEST_CASE("Parse required arguments which are not set and don't have default value.", "[required_arguments]") {
+	argparse::ArgumentParser program("test");
+	program.add_argument("--output", "-o").required();
+	REQUIRE_THROWS(program.parse_args({ "./main" }));
+}
+
+TEST_CASE("Parse required arguments which are set as empty value and don't have default value.", "[required_arguments]") {
+	argparse::ArgumentParser program("test");
+	program.add_argument("--output", "-o").required();
+	REQUIRE_THROWS(program.parse_args({ "./main", "-o" }));
+}
+
+TEST_CASE("Parse required arguments which are set as some value and don't have default value.", "[required_arguments]") {
+	argparse::ArgumentParser program("test");
+	program.add_argument("--output", "-o").required();
+	program.parse_args({ "./main", "-o", "filename" });
+	REQUIRE(program.get("--output") == "filename");
+	REQUIRE(program.get("-o") == "filename");
+}
+
+TEST_CASE("Parse required arguments which are not set and have default value.", "[required_arguments]") {
+	argparse::ArgumentParser program("test");
+	program.add_argument("--output", "-o").required().default_value(std::string("filename"));
+	program.parse_args({ "./main" });
+	REQUIRE(program.get("--output") == "filename");
+	REQUIRE(program.get("-o") == "filename");
+}
+
+TEST_CASE("Parse required arguments which are set as empty and have default value.", "[required_arguments]") {
+	argparse::ArgumentParser program("test");
+	program.add_argument("--output", "-o").required().default_value(std::string("filename"));
+	REQUIRE_THROWS(program.parse_args({ "./main", "-o" }));
+}
+
+TEST_CASE("Parse required arguments which are set as some value and have default value.", "[required_arguments]") {
+	argparse::ArgumentParser program("test");
+	program.add_argument("--output", "-o").required().default_value(std::string("filename"));
+	program.parse_args({ "./main", "-o", "anotherfile" });
+	REQUIRE(program.get("--output") == "anotherfile");
+	REQUIRE(program.get("-o") == "anotherfile");
+}
\ No newline at end of file