diff --git a/.github/workflows/compile-sketch.yml b/.github/workflows/compile-sketch.yml
index b79c527..1da9421 100644
--- a/.github/workflows/compile-sketch.yml
+++ b/.github/workflows/compile-sketch.yml
@@ -86,13 +86,13 @@ jobs:
               version: 3.0.5
           sketch-paths: |
             - examples/ml_epiano_example
-            #- examples/ml_mod_tracker
+            - examples/ml_mod_tracker
             - examples/ml_synth_basic_example
-            #- examples/ml_synth_fm_example
-            #- examples/ml_synth_multi_saw_example
-            #- examples/ml_synth_organ_example
-            #- examples/ml_synth_pwm_osc_example
-            #- examples/ml_synth_sampler_example
+            - examples/ml_synth_fm_example
+            - examples/ml_synth_multi_saw_example
+            - examples/ml_synth_organ_example
+            - examples/ml_synth_pwm_osc_example
+            - examples/ml_synth_sampler_example
           libraries: |
               - source-url: https://github.com/marcel-licence/ML_SynthTools.git
                 name: ML_SynthTools
diff --git a/src/caps_info.h b/src/caps_info.h
index fa5db21..dcba502 100644
--- a/src/caps_info.h
+++ b/src/caps_info.h
@@ -102,12 +102,12 @@ void CapsPrintInfo(void)
 void PrintMemoryInfo(void)
 {
 #ifdef ESP32
-    Serial.printf("ESP.getFreeHeap() %d\n", ESP.getFreeHeap());
-    Serial.printf("ESP.getMinFreeHeap() %d\n", ESP.getMinFreeHeap());
-    Serial.printf("ESP.getHeapSize() %d\n", ESP.getHeapSize());
-    Serial.printf("ESP.getMaxAllocHeap() %d\n", ESP.getMaxAllocHeap());
+    Serial.printf("ESP.getFreeHeap() %" PRIu32 "\n", ESP.getFreeHeap());
+    Serial.printf("ESP.getMinFreeHeap() %" PRIu32 "\n", ESP.getMinFreeHeap());
+    Serial.printf("ESP.getHeapSize() %" PRIu32 "\n", ESP.getHeapSize());
+    Serial.printf("ESP.getMaxAllocHeap() %" PRIu32 "\n", ESP.getMaxAllocHeap());
 
-    Serial.printf("Total PSRAM: %d\n", ESP.getPsramSize());
-    Serial.printf("Free PSRAM: %d\n", ESP.getFreePsram());
+    Serial.printf("Total PSRAM: %" PRIu32 "\n", ESP.getPsramSize());
+    Serial.printf("Free PSRAM: %" PRIu32 "\n", ESP.getFreePsram());
 #endif
 }
diff --git a/src/es8388.h b/src/es8388.h
index 85b8b15..3cb0202 100644
--- a/src/es8388.h
+++ b/src/es8388.h
@@ -394,7 +394,7 @@ void ES8388_Setup()
     Serial.printf("Connect to ES8388 codec...\n");
     Serial.printf("  SDA: %d\n ", ES8388_PIN_SDA);
     Serial.printf("  SCL: %d\n", ES8388_PIN_SCL);
-    Serial.printf("  freq: %d\n", i2c_freq);
+    Serial.printf("  freq: %" PRIu32 "\n", i2c_freq);
 
     while (not ES8388_begin(ES8388_PIN_SDA, ES8388_PIN_SCL, i2c_freq))
     {
diff --git a/src/esp32_audio_kit_module.h b/src/esp32_audio_kit_module.h
index 195c940..5b9b806 100644
--- a/src/esp32_audio_kit_module.h
+++ b/src/esp32_audio_kit_module.h
@@ -142,9 +142,13 @@ void ac101_mclk_setup()
 {
     uint32_t freq = SAMPLE_RATE * 512; /* The maximal frequency is 80000000 / 2^bit_num */
     Serial.printf("Output frequency: %d\n", freq);
+#if ESP_ARDUINO_VERSION_MAJOR < 3
     ledcSetup(MCLK_CH, freq, PWM_BIT);
     ledcAttachPin(OUTPUT_PIN, MCLK_CH);
     ledcWrite(MCLK_CH, 1 << (PWM_BIT - 1)); /* 50% duty -> The available duty levels are (2^bit_num)-1, where bit_num can be 1-15. */
+#else
+#warning MCLK not supported yet
+#endif
 }
 
 /*