diff --git a/src/TinyGsmClientA6.h b/src/TinyGsmClientA6.h
index aba1cf8..cc6f946 100644
--- a/src/TinyGsmClientA6.h
+++ b/src/TinyGsmClientA6.h
@@ -176,11 +176,11 @@ class TinyGsmA6 : public TinyGsmModem<TinyGsmA6>,
    * Power functions
    */
  protected:
-  bool restartImpl() {
+  bool restartImpl(const char* pin = NULL) {
     if (!testAT()) { return false; }
     sendAT(GF("+RST=1"));
     delay(3000);
-    return init();
+    return init(pin);
   }
 
   bool powerOffImpl() {
diff --git a/src/TinyGsmClientBG96.h b/src/TinyGsmClientBG96.h
index 245d923..41892cd 100644
--- a/src/TinyGsmClientBG96.h
+++ b/src/TinyGsmClientBG96.h
@@ -202,11 +202,11 @@ class TinyGsmBG96 : public TinyGsmModem<TinyGsmBG96>,
    * Power functions
    */
  protected:
-  bool restartImpl() {
+  bool restartImpl(const char* pin = NULL) {
     if (!testAT()) { return false; }
     if (!setPhoneFunctionality(1, true)) { return false; }
     waitResponse(10000L, GF("APP RDY"));
-    return init();
+    return init(pin);
   }
 
   bool powerOffImpl() {
diff --git a/src/TinyGsmClientESP8266.h b/src/TinyGsmClientESP8266.h
index b3244c7..0b5c7a6 100644
--- a/src/TinyGsmClientESP8266.h
+++ b/src/TinyGsmClientESP8266.h
@@ -182,13 +182,13 @@ class TinyGsmESP8266 : public TinyGsmModem<TinyGsmESP8266>,
    * Power functions
    */
  protected:
-  bool restartImpl() {
+  bool restartImpl(const char* pin = NULL) {
     if (!testAT()) { return false; }
     sendAT(GF("+RST"));
     if (waitResponse(10000L) != 1) { return false; }
     if (waitResponse(10000L, GF(GSM_NL "ready" GSM_NL)) != 1) { return false; }
     delay(500);
-    return init();
+    return init(pin);
   }
 
   bool powerOffImpl() {
diff --git a/src/TinyGsmClientM590.h b/src/TinyGsmClientM590.h
index c234941..43804e2 100644
--- a/src/TinyGsmClientM590.h
+++ b/src/TinyGsmClientM590.h
@@ -171,12 +171,12 @@ class TinyGsmM590 : public TinyGsmModem<TinyGsmM590>,
    * Power functions
    */
  protected:
-  bool restartImpl() {
+  bool restartImpl(const char* pin = NULL) {
     if (!testAT()) { return false; }
     if (!setPhoneFunctionality(15)) { return false; }
     // MODEM:STARTUP
     waitResponse(60000L, GF(GSM_NL "+PBREADY" GSM_NL));
-    return init();
+    return init(pin);
   }
 
   bool powerOffImpl() {
diff --git a/src/TinyGsmClientM95.h b/src/TinyGsmClientM95.h
index a853512..538969a 100644
--- a/src/TinyGsmClientM95.h
+++ b/src/TinyGsmClientM95.h
@@ -198,7 +198,7 @@ class TinyGsmM95 : public TinyGsmModem<TinyGsmM95>,
    * Power functions
    */
  protected:
-  bool restartImpl() {
+  bool restartImpl(const char* pin = NULL) {
     if (!testAT()) { return false; }
     sendAT(GF("+CFUN=0"));
     if (waitResponse(10000L, GF("NORMAL POWER DOWN"), GF("OK"), GF("FAIL")) ==
@@ -209,7 +209,7 @@ class TinyGsmM95 : public TinyGsmModem<TinyGsmM95>,
     if (waitResponse(10000L, GF("Call Ready"), GF("OK"), GF("FAIL")) == 3) {
       return false;
     }
-    return init();
+    return init(pin);
   }
 
   bool powerOffImpl() {
diff --git a/src/TinyGsmClientMC60.h b/src/TinyGsmClientMC60.h
index 7eb2c4b..9d30ef1 100644
--- a/src/TinyGsmClientMC60.h
+++ b/src/TinyGsmClientMC60.h
@@ -197,12 +197,12 @@ class TinyGsmMC60 : public TinyGsmModem<TinyGsmMC60>,
    * Power functions
    */
  protected:
-  bool restartImpl() {
+  bool restartImpl(const char* pin = NULL) {
     if (!testAT()) { return false; }
     if (!setPhoneFunctionality(0)) { return false; }
     if (!setPhoneFunctionality(1, true)) { return false; }
     delay(3000);
-    return init();
+    return init(pin);
   }
 
   bool powerOffImpl() {
diff --git a/src/TinyGsmClientSIM5360.h b/src/TinyGsmClientSIM5360.h
index 536d0d6..c4c2b83 100644
--- a/src/TinyGsmClientSIM5360.h
+++ b/src/TinyGsmClientSIM5360.h
@@ -215,7 +215,7 @@ class TinyGsmSim5360 : public TinyGsmModem<TinyGsmSim5360>,
    * Power functions
    */
  protected:
-  bool restartImpl() {
+  bool restartImpl(const char* pin = NULL) {
     if (!testAT()) { return false; }
     sendAT(GF("+REBOOT"));
     // Should return an 'OK' after reboot command is sent
@@ -223,7 +223,7 @@ class TinyGsmSim5360 : public TinyGsmModem<TinyGsmSim5360>,
     // After booting, modem sends out messages as each of its
     // internal modules loads.  The final message is "PB DONE".
     if (waitResponse(40000L, GF(GSM_NL "PB DONE")) != 1) { return false; }
-    return init();
+    return init(pin);
   }
 
   bool powerOffImpl() {
diff --git a/src/TinyGsmClientSIM7000.h b/src/TinyGsmClientSIM7000.h
index 4a9e751..0934bf4 100644
--- a/src/TinyGsmClientSIM7000.h
+++ b/src/TinyGsmClientSIM7000.h
@@ -212,11 +212,11 @@ class TinyGsmSim7000 : public TinyGsmModem<TinyGsmSim7000>,
    * Power functions
    */
  protected:
-  bool restartImpl() {
+  bool restartImpl(const char* pin = NULL) {
     if (!setPhoneFunctionality(0)) { return false; }
     if (!setPhoneFunctionality(1, true)) { return false; }
     waitResponse(10000L, GF("SMS Ready"), GF("RDY"));
-    return init();
+    return init(pin);
   }
 
   bool powerOffImpl() {
diff --git a/src/TinyGsmClientSIM7600.h b/src/TinyGsmClientSIM7600.h
index b592853..ae2220d 100644
--- a/src/TinyGsmClientSIM7600.h
+++ b/src/TinyGsmClientSIM7600.h
@@ -219,12 +219,12 @@ class TinyGsmSim7600 : public TinyGsmModem<TinyGsmSim7600>,
    * Power functions
    */
  protected:
-  bool restartImpl() {
+  bool restartImpl(const char* pin = NULL) {
     if (!testAT()) { return false; }
     sendAT(GF("+CRESET"));
     if (waitResponse(10000L) != 1) { return false; }
     delay(5000L);  // TODO(?):  Test this delay!
-    return init();
+    return init(pin);
   }
 
   bool powerOffImpl() {
diff --git a/src/TinyGsmClientSIM800.h b/src/TinyGsmClientSIM800.h
index b78ac98..3754eb5 100644
--- a/src/TinyGsmClientSIM800.h
+++ b/src/TinyGsmClientSIM800.h
@@ -250,14 +250,14 @@ class TinyGsmSim800 : public TinyGsmModem<TinyGsmSim800>,
    * Power functions
    */
  protected:
-  bool restartImpl() {
+  bool restartImpl(const char* pin = NULL) {
     if (!testAT()) { return false; }
     sendAT(GF("&W"));
     waitResponse();
     if (!setPhoneFunctionality(0)) { return false; }
     if (!setPhoneFunctionality(1, true)) { return false; }
     delay(3000);
-    return init();
+    return init(pin);
   }
 
   bool powerOffImpl() {
diff --git a/src/TinyGsmClientSaraR4.h b/src/TinyGsmClientSaraR4.h
index 30ccb81..8cc0b4d 100644
--- a/src/TinyGsmClientSaraR4.h
+++ b/src/TinyGsmClientSaraR4.h
@@ -297,11 +297,11 @@ class TinyGsmSaraR4 : public TinyGsmModem<TinyGsmSaraR4>,
    */
  protected:
   // using +CFUN=15 instead of the more common CFUN=1,1
-  bool restartImpl() {
+  bool restartImpl(const char* pin = NULL) {
     if (!testAT()) { return false; }
     if (!setPhoneFunctionality(15)) { return false; }
     delay(3000);  // TODO(?):  Verify delay timing here
-    return init();
+    return init(pin);
   }
 
   bool powerOffImpl() {
diff --git a/src/TinyGsmClientSequansMonarch.h b/src/TinyGsmClientSequansMonarch.h
index 1a997db..855c166 100644
--- a/src/TinyGsmClientSequansMonarch.h
+++ b/src/TinyGsmClientSequansMonarch.h
@@ -283,7 +283,7 @@ class TinyGsmSequansMonarch
    * Power functions
    */
  protected:
-  bool restartImpl() {
+  bool restartImpl(const char* pin = NULL) {
     if (!testAT()) { return false; }
 
     sendAT(GF("+CFUN=0"));
@@ -295,7 +295,7 @@ class TinyGsmSequansMonarch
     res = waitResponse(20000L, GF("+SYSSTART"), GFP(GSM_ERROR));
     if (res != 1 && res != 3) { return false; }
     delay(1000);
-    return init();
+    return init(pin);
   }
 
   bool powerOffImpl() {
diff --git a/src/TinyGsmClientUBLOX.h b/src/TinyGsmClientUBLOX.h
index 600dcd7..ce27d99 100644
--- a/src/TinyGsmClientUBLOX.h
+++ b/src/TinyGsmClientUBLOX.h
@@ -243,11 +243,11 @@ class TinyGsmUBLOX : public TinyGsmModem<TinyGsmUBLOX>,
    * Power functions
    */
  protected:
-  bool restartImpl() {
+  bool restartImpl(const char* pin = NULL) {
     if (!testAT()) { return false; }
     if (!setPhoneFunctionality(16)) { return false; }
     delay(3000);  // TODO(?):  Verify delay timing here
-    return init();
+    return init(pin);
   }
 
   bool powerOffImpl() {
diff --git a/src/TinyGsmClientXBee.h b/src/TinyGsmClientXBee.h
index cd8320d..a360631 100644
--- a/src/TinyGsmClientXBee.h
+++ b/src/TinyGsmClientXBee.h
@@ -487,7 +487,7 @@ class TinyGsmXBee : public TinyGsmModem<TinyGsmXBee>,
     }
   }
 
-  bool restartImpl() {
+  bool restartImpl(const char* pin = NULL) {
     if (!commandMode()) { return false; }  // Return immediately
 
     if (beeType == XBEE_UNKNOWN) getSeries();  // how we restart depends on this
@@ -525,7 +525,7 @@ class TinyGsmXBee : public TinyGsmModem<TinyGsmXBee>,
 
     exitCommand();
 
-    return init();
+    return init(pin);
   }
 
   void setupPinSleep(bool maintainAssociation = false) {
diff --git a/src/TinyGsmModem.tpp b/src/TinyGsmModem.tpp
index d22770f..1f2f928 100644
--- a/src/TinyGsmModem.tpp
+++ b/src/TinyGsmModem.tpp
@@ -53,8 +53,8 @@ class TinyGsmModem {
   /*
    * Power functions
    */
-  bool restart() {
-    return thisModem().restartImpl();
+  bool restart(const char* pin = NULL) {
+    return thisModem().restartImpl(pin);
   }
   bool poweroff() {
     return thisModem().powerOffImpl();