diff --git a/cores/esp32/Esp.cpp b/cores/esp32/Esp.cpp
index aa73e698bbe..ecbf4877d90 100644
--- a/cores/esp32/Esp.cpp
+++ b/cores/esp32/Esp.cpp
@@ -131,7 +131,7 @@ unsigned long long operator"" _GB(unsigned long long x)
 
 EspClass ESP;
 
-void EspClass::deepSleep(uint32_t time_us)
+void EspClass::deepSleep(uint64_t time_us)
 {
     esp_deep_sleep(time_us);
 }
diff --git a/cores/esp32/Esp.h b/cores/esp32/Esp.h
index 478158ddf1f..82dd25e3c25 100644
--- a/cores/esp32/Esp.h
+++ b/cores/esp32/Esp.h
@@ -86,7 +86,7 @@ class EspClass
     const char * getSdkVersion(); //version of ESP-IDF
     const char * getCoreVersion();//version of this core
 
-    void deepSleep(uint32_t time_us);
+    void deepSleep(uint64_t time_us);
 
     uint32_t getFlashChipSize();
     uint32_t getFlashChipSpeed();