diff --git a/.github/workflows/build.yml b/.github/workflows/build.yml
new file mode 100644
index 000000000..cfcb590a7
--- /dev/null
+++ b/.github/workflows/build.yml
@@ -0,0 +1,36 @@
+name: Build
+
+on: [push, pull_request]
+
+jobs:
+  build:
+    strategy:
+      matrix:
+        idf_ver: ["latest", "release-v4.1", "release-v4.2", "release-v4.3", "release-v4.4"]
+        example: ["pppos_client", "modem_console", "ap_to_pppos", "simple_cmux_client"]
+        idf_target: ["esp32"]        
+        exclude:
+          - idf_ver: "release-v4.1"
+            example: modem_console
+          - idf_ver: "release-v4.1"
+            example: ap_to_pppos
+          - idf_ver: "release-v4.1"
+            example: simple_cmux_client
+          - idf_ver: "release-v4.2"
+            example: simple_cmux_client
+
+    runs-on: ubuntu-20.04
+    container: espressif/idf:${{ matrix.idf_ver }}
+    steps:
+      - name: Checkout esp-protocols
+        uses: actions/checkout@master
+        with:
+          path: esp-protocols
+      - name: Build ${{ matrix.example }} with IDF-${{ matrix.idf_ver }} for ${{ matrix.idf_target }}
+        env:
+          IDF_TARGET: ${{ matrix.idf_target }}
+        shell: bash
+        run: |
+          . ${IDF_PATH}/export.sh
+          cd $GITHUB_WORKSPACE/esp-protocols/components/esp_modem/examples/${{ matrix.example }}
+          idf.py build
diff --git a/components/esp_modem/examples/ap_to_pppos/main/network_dce.c b/components/esp_modem/examples/ap_to_pppos/main/network_dce.c
index 499593aa2..8c825a0fd 100644
--- a/components/esp_modem/examples/ap_to_pppos/main/network_dce.c
+++ b/components/esp_modem/examples/ap_to_pppos/main/network_dce.c
@@ -25,6 +25,7 @@ esp_err_t modem_init_network(esp_netif_t *netif)
         return ESP_FAIL;
     }
 
+#ifdef CONFIG_EXAMPLE_NEED_SIM_PIN
     // configure the PIN
     bool pin_ok = false;
     if (esp_modem_read_pin(dce, &pin_ok) == ESP_OK && pin_ok == false) {
@@ -34,6 +35,7 @@ esp_err_t modem_init_network(esp_netif_t *netif)
             abort();
         }
     }
+#endif // CONFIG_EXAMPLE_NEED_SIM_PIN
     return ESP_OK;
 }
 
diff --git a/components/esp_modem/examples/modem_console/main/httpget_handle.c b/components/esp_modem/examples/modem_console/main/httpget_handle.c
index da15b75d9..71eb219c9 100644
--- a/components/esp_modem/examples/modem_console/main/httpget_handle.c
+++ b/components/esp_modem/examples/modem_console/main/httpget_handle.c
@@ -83,9 +83,9 @@ static int do_http_client(int argc, char **argv)
 
     esp_err_t err = esp_http_client_perform(client);
     if (err == ESP_OK) {
-        ESP_LOGI(TAG, "HTTP GET Status = %d, content_length = %d",
-                 esp_http_client_get_status_code(client),
-                 esp_http_client_get_content_length(client));
+        uint64_t content_length = esp_http_client_get_content_length(client);
+        ESP_LOGI(TAG, "HTTP GET Status = %d, content_length = %lld",
+                 esp_http_client_get_status_code(client), content_length);
         return 0;
     }
     ESP_LOGE(TAG, "HTTP GET request failed: %s", esp_err_to_name(err));
diff --git a/components/esp_modem/examples/simple_cmux_client/sdkconfig.defaults b/components/esp_modem/examples/simple_cmux_client/sdkconfig.defaults
index 7841f6833..b6fa51455 100644
--- a/components/esp_modem/examples/simple_cmux_client/sdkconfig.defaults
+++ b/components/esp_modem/examples/simple_cmux_client/sdkconfig.defaults
@@ -6,6 +6,7 @@ CONFIG_LWIP_TCPIP_TASK_STACK_SIZE=4096
 CONFIG_LWIP_PPP_ENABLE_IPV6=n
 CONFIG_COMPILER_CXX_EXCEPTIONS=y
 CONFIG_PARTITION_TABLE_TWO_OTA=y
+CONFIG_ESPTOOLPY_FLASHSIZE_4MB=y
 CONFIG_NEWLIB_STDOUT_LINE_ENDING_LF=y
 CONFIG_NEWLIB_STDIN_LINE_ENDING_LF=y
 CONFIG_MAIN_TASK_STACK_SIZE=8192
\ No newline at end of file