diff --git a/.github/workflows/c-cpp-cmake.yml b/.github/workflows/c-cpp-cmake.yml
index 66a5cda..0546e0e 100644
--- a/.github/workflows/c-cpp-cmake.yml
+++ b/.github/workflows/c-cpp-cmake.yml
@@ -13,5 +13,7 @@ jobs:
 
     steps:
     - uses: actions/checkout@v4
+      with:
+        submodules: 'true'
     - name: build.sh
       run: ./build.sh
\ No newline at end of file
diff --git a/.github/workflows/unit-tests.yml b/.github/workflows/unit-tests.yml
index b7c9311..8897b9a 100644
--- a/.github/workflows/unit-tests.yml
+++ b/.github/workflows/unit-tests.yml
@@ -25,6 +25,8 @@ jobs:
     steps:
       - name: Checkout repository
         uses: actions/checkout@v2
+        with:
+          submodules: 'true'
 
       - name: Relax some warings
         # run: echo 'add_compile_options(-Wno-unused-function)' >> ArduinoCore-API/test/CMakeLists.txt
@@ -51,4 +53,4 @@ jobs:
       #  with:
       #    token: ${{ secrets.CODECOV_TOKEN }}
       #    files: ${{ env.COVERAGE_DATA_PATH }}
-      #    fail_ci_if_error: true
\ No newline at end of file
+      #    fail_ci_if_error: true
diff --git a/ArduinoCore-Linux/cores/arduino/EthernetUDP.h b/ArduinoCore-Linux/cores/arduino/EthernetUDP.h
index 9edc2f0..17b87d8 100644
--- a/ArduinoCore-Linux/cores/arduino/EthernetUDP.h
+++ b/ArduinoCore-Linux/cores/arduino/EthernetUDP.h
@@ -34,8 +34,8 @@
  * bjoern@cs.stanford.edu 12/30/2008
  */
 
-#include <api/IPAddress.h>
-#include <api/Udp.h>
+#include "api/IPAddress.h"
+#include "api/Udp.h"
 #include <RingBufferExt.h>
 #include "SignalHandler.h"
 #include "ArduinoLogger.h"
diff --git a/ArduinoCore-Linux/cores/arduino/FileStream.h b/ArduinoCore-Linux/cores/arduino/FileStream.h
index c2dbd2a..c9c29fe 100644
--- a/ArduinoCore-Linux/cores/arduino/FileStream.h
+++ b/ArduinoCore-Linux/cores/arduino/FileStream.h
@@ -2,7 +2,7 @@
 
 #include <iostream>
 #include <fstream>
-#include "Stream.h"
+#include "api/Stream.h"
 
 namespace arduino {
 
diff --git a/ArduinoCore-Linux/cores/arduino/Serial.h b/ArduinoCore-Linux/cores/arduino/Serial.h
index 35be4d7..6b1946f 100644
--- a/ArduinoCore-Linux/cores/arduino/Serial.h
+++ b/ArduinoCore-Linux/cores/arduino/Serial.h
@@ -3,7 +3,7 @@
 #if USE_SERIALLIB
 
 #include "serialib.h"
-#include "HardwareSerial.h"
+#include "api/HardwareSerial.h"
 
 namespace arduino {
 
diff --git a/ArduinoCore-Linux/cores/arduino/StdioDevice.h b/ArduinoCore-Linux/cores/arduino/StdioDevice.h
index d70b571..db9aa73 100644
--- a/ArduinoCore-Linux/cores/arduino/StdioDevice.h
+++ b/ArduinoCore-Linux/cores/arduino/StdioDevice.h
@@ -2,8 +2,8 @@
 
 #include <iostream>
 #include <streambuf>
-#include "Stream.h"
-#include "Printable.h"
+#include "api/Stream.h"
+#include "api/Printable.h"
 
 namespace arduino {
 
diff --git a/ArduinoCore-Linux/cores/rasperry_pi/HardwareI2C_RPI.h b/ArduinoCore-Linux/cores/rasperry_pi/HardwareI2C_RPI.h
index 9120f38..093b966 100644
--- a/ArduinoCore-Linux/cores/rasperry_pi/HardwareI2C_RPI.h
+++ b/ArduinoCore-Linux/cores/rasperry_pi/HardwareI2C_RPI.h
@@ -5,7 +5,7 @@
 #include <unistd.h>  // for open(), close(), etc.
 #include <vector>
 #include "Hardware.h"
-#include "HardwareI2C.h"
+#include "api/HardwareI2C.h"
 #include "ArduinoLogger.h"
 
 namespace arduino {
diff --git a/ArduinoCore-Linux/cores/rasperry_pi/HardwareSPI_RPI.h b/ArduinoCore-Linux/cores/rasperry_pi/HardwareSPI_RPI.h
index 044c97a..27aa5fa 100644
--- a/ArduinoCore-Linux/cores/rasperry_pi/HardwareSPI_RPI.h
+++ b/ArduinoCore-Linux/cores/rasperry_pi/HardwareSPI_RPI.h
@@ -2,9 +2,9 @@
 #ifdef USE_RPI
 #include <inttypes.h>
 
-#include "Common.h"
-#include "HardwareSPI.h"
-#include "Stream.h"
+#include "api/Common.h"
+#include "api/HardwareSPI.h"
+#include "api/Stream.h"
 
 namespace arduino {
 
diff --git a/CMakeLists.txt b/CMakeLists.txt
index fe69c7d..235accd 100644
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -44,7 +44,7 @@ target_include_directories (arduino_emulator PUBLIC
 
 # Install header files 
 install(DIRECTORY "${CMAKE_CURRENT_SOURCE_DIR}/ArduinoCore-API/api/" # source directory
-    DESTINATION "include/arduino" # target directory
+    DESTINATION "include/arduino/api" # target directory
     FILES_MATCHING # install only matched files
     PATTERN "*.h" # select header files
 )