diff --git a/CMakeLists.txt b/CMakeLists.txt
index 2d78f85..9e97d5f 100644
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -25,4 +25,13 @@ add_subdirectory(extern/catch2)
 # Include all internal subprojects (library, examples, testing).
 add_subdirectory(lib/pls)
 
-add_subdirectory(app/playground)
\ No newline at end of file
+# Include examples
+add_subdirectory(app/playground)
+
+# Add optional tests
+option(PACKAGE_TESTS "Build the tests" ON)
+if(PACKAGE_TESTS)
+    enable_testing()
+    add_subdirectory(test)
+    add_test(NAME AllTests COMMAND tests)
+endif()
diff --git a/lib/pls/include/pls/library.h b/lib/pls/include/pls/library.h
index 6c821dc..6efc19f 100644
--- a/lib/pls/include/pls/library.h
+++ b/lib/pls/include/pls/library.h
@@ -3,6 +3,7 @@
 
 namespace pls {
     void hello();
+    int test_adder(int a, int b);
 }
 
 #endif
\ No newline at end of file
diff --git a/lib/pls/src/library.cpp b/lib/pls/src/library.cpp
index 2339915..6634af0 100644
--- a/lib/pls/src/library.cpp
+++ b/lib/pls/src/library.cpp
@@ -6,4 +6,8 @@ namespace pls {
     void hello() {
         std::cout << "Hello from PLS!" << std::endl;
     }
+
+    int test_adder(int a, int b) {
+        return a + b;
+    }
 }
\ No newline at end of file
diff --git a/test/CMakeLists.txt b/test/CMakeLists.txt
new file mode 100644
index 0000000..929af12
--- /dev/null
+++ b/test/CMakeLists.txt
@@ -0,0 +1,4 @@
+add_executable(tests
+        main.cpp
+        example_tests.cpp)
+target_link_libraries(tests catch2 pls)
\ No newline at end of file
diff --git a/test/example_tests.cpp b/test/example_tests.cpp
new file mode 100644
index 0000000..7774ebf
--- /dev/null
+++ b/test/example_tests.cpp
@@ -0,0 +1,22 @@
+#include <catch.hpp>
+#include <pls/library.h>
+
+// BDD style
+SCENARIO( "the test_adder works", "[library]" ) {
+    GIVEN ("two numbers") {
+        WHEN ( "they are positive") {
+            THEN ( "the result is positive") {
+                REQUIRE(pls::test_adder(1, 2) >= 0);
+            }
+            THEN ( "the result is the sum of both") {
+                REQUIRE(pls::test_adder(1, 4) == 5);
+            }
+        }
+    }
+}
+
+
+// Normal Style
+TEST_CASE( "the test_adder can sumup", "[libray]") {
+    
+}
\ No newline at end of file
diff --git a/test/main.cpp b/test/main.cpp
new file mode 100644
index 0000000..6fb1ee3
--- /dev/null
+++ b/test/main.cpp
@@ -0,0 +1,3 @@
+#define CATCH_CONFIG_MAIN
+#include <catch.hpp>
+