diff --git a/examples/coremark/platformio.ini b/examples/coremark/platformio.ini
index 3777076..bbc929f 100644
--- a/examples/coremark/platformio.ini
+++ b/examples/coremark/platformio.ini
@@ -11,6 +11,8 @@
 [platformio]
 description = 
 	CoreMark benchmark.
+# uncomment below and select default environment
+; default_envs = nuclei_fpga_eval
 
 [common]
 300_flags = -Ofast -fno-code-hoisting -fno-tree-vectorize -fno-common -finline-functions -falign-functions=4
diff --git a/examples/cpuinfo/platformio.ini b/examples/cpuinfo/platformio.ini
index 5d41340..7aadab8 100644
--- a/examples/cpuinfo/platformio.ini
+++ b/examples/cpuinfo/platformio.ini
@@ -10,6 +10,8 @@
 [platformio]
 description =
     Probe and dump Nuclei RISC-V Processor Info
+# uncomment below and select default environment
+; default_envs = nuclei_fpga_eval
 
 [env]
 platform = nuclei
diff --git a/examples/demo_dsp/platformio.ini b/examples/demo_dsp/platformio.ini
index b6d6aa5..c00587c 100644
--- a/examples/demo_dsp/platformio.ini
+++ b/examples/demo_dsp/platformio.ini
@@ -10,6 +10,8 @@
 [platformio]
 description =
     example to show how to use NMSIS DSP Library.
+# uncomment below and select default environment
+; default_envs = nuclei_fpga_eval
 
 [env]
 platform = nuclei
diff --git a/examples/demo_eclic/platformio.ini b/examples/demo_eclic/platformio.ini
index d36c0a2..f3d113b 100644
--- a/examples/demo_eclic/platformio.ini
+++ b/examples/demo_eclic/platformio.ini
@@ -10,6 +10,8 @@
 [platformio]
 description =
     example to show how to use ECLIC and interrupt.
+# uncomment below and select default environment
+; default_envs = nuclei_fpga_eval
 
 [env]
 platform = nuclei
diff --git a/examples/dhrystone/platformio.ini b/examples/dhrystone/platformio.ini
index a5cd9af..571cf5b 100644
--- a/examples/dhrystone/platformio.ini
+++ b/examples/dhrystone/platformio.ini
@@ -10,6 +10,8 @@
 [platformio]
 description =
     Dhyrstone benchmark.
+# uncomment below and select default environment
+; default_envs = nuclei_fpga_eval
 
 [common]
 compile_flags = -O3 -fno-inline -funroll-loops
diff --git a/examples/freertos_demo/platformio.ini b/examples/freertos_demo/platformio.ini
index 65b8951..33a8a45 100644
--- a/examples/freertos_demo/platformio.ini
+++ b/examples/freertos_demo/platformio.ini
@@ -11,6 +11,8 @@
 [platformio]
 description =
     A simple FreeRTOS demo to demonstrate FreeRTOS usage and build environment.
+# uncomment below and select default environment
+; default_envs = nuclei_fpga_eval
 
 [env]
 platform = nuclei
diff --git a/examples/helloworld/platformio.ini b/examples/helloworld/platformio.ini
index 21ab9c3..adef636 100644
--- a/examples/helloworld/platformio.ini
+++ b/examples/helloworld/platformio.ini
@@ -10,6 +10,8 @@
 [platformio]
 description =
     A simple "Hello, World!" example to demonstrate printf and build environment.
+# uncomment below and select default environment
+; default_envs = nuclei_fpga_eval
 
 [env]
 platform = nuclei
diff --git a/examples/rtthread_demo/platformio.ini b/examples/rtthread_demo/platformio.ini
index a453243..dd79448 100644
--- a/examples/rtthread_demo/platformio.ini
+++ b/examples/rtthread_demo/platformio.ini
@@ -11,6 +11,8 @@
 [platformio]
 description =
     A simple RT-Thread demo to demonstrate RT-Thread usage and build environment.
+# uncomment below and select default environment
+; default_envs = nuclei_fpga_eval
 
 [env]
 platform = nuclei
diff --git a/examples/ucosii_demo/platformio.ini b/examples/ucosii_demo/platformio.ini
index 1bc08a7..539eca5 100644
--- a/examples/ucosii_demo/platformio.ini
+++ b/examples/ucosii_demo/platformio.ini
@@ -11,6 +11,8 @@
 [platformio]
 description =
     A simple UCOSII demo to demonstrate UCOSII usage and build environment.
+# uncomment below and select default environment
+; default_envs = nuclei_fpga_eval
 
 [env]
 platform = nuclei
diff --git a/examples/whetstone/platformio.ini b/examples/whetstone/platformio.ini
index 1927242..0ec4a05 100644
--- a/examples/whetstone/platformio.ini
+++ b/examples/whetstone/platformio.ini
@@ -10,6 +10,8 @@
 [platformio]
 description =
     Whestone benchmark.
+# uncomment below and select default environment
+; default_envs = nuclei_fpga_eval
 
 [common]
 compile_flags = -O3 -funroll-loops -fsingle-precision-constant