diff --git a/.travis.yml b/.travis.yml
index 251a6212b..bb9db5bed 100644
--- a/.travis.yml
+++ b/.travis.yml
@@ -209,7 +209,7 @@ script:
   #
   - restore_configs
   - opt_enable_adv BEZIER_CURVE_SUPPORT EXPERIMENTAL_I2CBUS
-  - opt_set_adv I2C_SLAVE_ADDRESS 1
+  - opt_set_adv I2C_SLAVE_ADDRESS 63
   - build_marlin
   #
   # Enable COREXY
diff --git a/Marlin/Configuration_adv.h b/Marlin/Configuration_adv.h
index 2def9b386..528d1f37e 100644
--- a/Marlin/Configuration_adv.h
+++ b/Marlin/Configuration_adv.h
@@ -795,6 +795,6 @@ const unsigned int dropsegments = 5; //everything with less than this number of
 // @section i2cbus
 
 //#define EXPERIMENTAL_I2CBUS
-#define I2C_SLAVE_ADDRESS  0 // Set non-zero to act as a slave
+#define I2C_SLAVE_ADDRESS  0 // Set a value from 8 to 127 to act as a slave
 
 #endif // CONFIGURATION_ADV_H
diff --git a/Marlin/Marlin_main.cpp b/Marlin/Marlin_main.cpp
index 0866a08dd..0a385622b 100644
--- a/Marlin/Marlin_main.cpp
+++ b/Marlin/Marlin_main.cpp
@@ -5294,7 +5294,7 @@ inline void gcode_M121() { endstops.enable_globally(false); }
     }
   }
 
-#endif //EXPERIMENTAL_I2CBUS
+#endif // EXPERIMENTAL_I2CBUS
 
 /**
  * M200: Set filament diameter and set E axis units to cubic units
diff --git a/Marlin/SanityCheck.h b/Marlin/SanityCheck.h
index cc8625e8f..fc866b121 100644
--- a/Marlin/SanityCheck.h
+++ b/Marlin/SanityCheck.h
@@ -747,3 +747,14 @@
 #if ENABLED(EMERGENCY_PARSER) && defined(USBCON)
   #error "EMERGENCY_PARSER does not work on boards with AT90USB processors (USBCON)."
 #endif
+
+/**
+ * I2C bus
+ */
+#if ENABLED(EXPERIMENTAL_I2CBUS) && I2C_SLAVE_ADDRESS > 0
+  #if I2C_SLAVE_ADDRESS < 8
+    #error "I2C_SLAVE_ADDRESS can't be less than 8. (Addresses 0 - 7 are reserved.)"
+  #elif I2C_SLAVE_ADDRESS > 127
+    #error "I2C_SLAVE_ADDRESS can't be over 127. (Only 7 bits allowed.)"
+  #endif
+#endif
diff --git a/Marlin/example_configurations/Cartesio/Configuration_adv.h b/Marlin/example_configurations/Cartesio/Configuration_adv.h
index 444fc7b2d..3f1287e11 100644
--- a/Marlin/example_configurations/Cartesio/Configuration_adv.h
+++ b/Marlin/example_configurations/Cartesio/Configuration_adv.h
@@ -795,6 +795,6 @@ const unsigned int dropsegments = 5; //everything with less than this number of
 // @section i2cbus
 
 //#define EXPERIMENTAL_I2CBUS
-#define I2C_SLAVE_ADDRESS  0 // Set non-zero to act as a slave
+#define I2C_SLAVE_ADDRESS  0 // Set a value from 8 to 127 to act as a slave
 
 #endif // CONFIGURATION_ADV_H
diff --git a/Marlin/example_configurations/Felix/Configuration_adv.h b/Marlin/example_configurations/Felix/Configuration_adv.h
index 6f4d1139c..d87f8a39e 100644
--- a/Marlin/example_configurations/Felix/Configuration_adv.h
+++ b/Marlin/example_configurations/Felix/Configuration_adv.h
@@ -795,6 +795,6 @@ const unsigned int dropsegments = 5; //everything with less than this number of
 // @section i2cbus
 
 //#define EXPERIMENTAL_I2CBUS
-#define I2C_SLAVE_ADDRESS  0 // Set non-zero to act as a slave
+#define I2C_SLAVE_ADDRESS  0 // Set a value from 8 to 127 to act as a slave
 
 #endif // CONFIGURATION_ADV_H
diff --git a/Marlin/example_configurations/Hephestos/Configuration_adv.h b/Marlin/example_configurations/Hephestos/Configuration_adv.h
index d26e2207b..452f5da81 100644
--- a/Marlin/example_configurations/Hephestos/Configuration_adv.h
+++ b/Marlin/example_configurations/Hephestos/Configuration_adv.h
@@ -795,6 +795,6 @@ const unsigned int dropsegments = 5; //everything with less than this number of
 // @section i2cbus
 
 //#define EXPERIMENTAL_I2CBUS
-#define I2C_SLAVE_ADDRESS  0 // Set non-zero to act as a slave
+#define I2C_SLAVE_ADDRESS  0 // Set a value from 8 to 127 to act as a slave
 
 #endif // CONFIGURATION_ADV_H
diff --git a/Marlin/example_configurations/Hephestos_2/Configuration_adv.h b/Marlin/example_configurations/Hephestos_2/Configuration_adv.h
index 4b771d5d5..9ee0941d5 100644
--- a/Marlin/example_configurations/Hephestos_2/Configuration_adv.h
+++ b/Marlin/example_configurations/Hephestos_2/Configuration_adv.h
@@ -795,6 +795,6 @@ const unsigned int dropsegments = 5; //everything with less than this number of
 // @section i2cbus
 
 //#define EXPERIMENTAL_I2CBUS
-#define I2C_SLAVE_ADDRESS  0 // Set non-zero to act as a slave
+#define I2C_SLAVE_ADDRESS  0 // Set a value from 8 to 127 to act as a slave
 
 #endif // CONFIGURATION_ADV_H
diff --git a/Marlin/example_configurations/K8200/Configuration_adv.h b/Marlin/example_configurations/K8200/Configuration_adv.h
index 92a81b22c..bf764d0f9 100644
--- a/Marlin/example_configurations/K8200/Configuration_adv.h
+++ b/Marlin/example_configurations/K8200/Configuration_adv.h
@@ -801,6 +801,6 @@ const unsigned int dropsegments = 2; //everything with less than this number of
 // @section i2cbus
 
 //#define EXPERIMENTAL_I2CBUS
-#define I2C_SLAVE_ADDRESS  0 // Set non-zero to act as a slave
+#define I2C_SLAVE_ADDRESS  0 // Set a value from 8 to 127 to act as a slave
 
 #endif // CONFIGURATION_ADV_H
diff --git a/Marlin/example_configurations/K8400/Configuration_adv.h b/Marlin/example_configurations/K8400/Configuration_adv.h
index dde4547f4..b5933588f 100644
--- a/Marlin/example_configurations/K8400/Configuration_adv.h
+++ b/Marlin/example_configurations/K8400/Configuration_adv.h
@@ -795,6 +795,6 @@ const unsigned int dropsegments = 5; //everything with less than this number of
 // @section i2cbus
 
 //#define EXPERIMENTAL_I2CBUS
-#define I2C_SLAVE_ADDRESS  0 // Set non-zero to act as a slave
+#define I2C_SLAVE_ADDRESS  0 // Set a value from 8 to 127 to act as a slave
 
 #endif // CONFIGURATION_ADV_H
diff --git a/Marlin/example_configurations/RigidBot/Configuration_adv.h b/Marlin/example_configurations/RigidBot/Configuration_adv.h
index d077ae28e..f8c8008df 100644
--- a/Marlin/example_configurations/RigidBot/Configuration_adv.h
+++ b/Marlin/example_configurations/RigidBot/Configuration_adv.h
@@ -795,6 +795,6 @@ const unsigned int dropsegments = 5; //everything with less than this number of
 // @section i2cbus
 
 //#define EXPERIMENTAL_I2CBUS
-#define I2C_SLAVE_ADDRESS  0 // Set non-zero to act as a slave
+#define I2C_SLAVE_ADDRESS  0 // Set a value from 8 to 127 to act as a slave
 
 #endif // CONFIGURATION_ADV_H
diff --git a/Marlin/example_configurations/SCARA/Configuration_adv.h b/Marlin/example_configurations/SCARA/Configuration_adv.h
index bf4d32351..3da8d5658 100644
--- a/Marlin/example_configurations/SCARA/Configuration_adv.h
+++ b/Marlin/example_configurations/SCARA/Configuration_adv.h
@@ -795,6 +795,6 @@ const unsigned int dropsegments = 5; //everything with less than this number of
 // @section i2cbus
 
 //#define EXPERIMENTAL_I2CBUS
-#define I2C_SLAVE_ADDRESS  0 // Set non-zero to act as a slave
+#define I2C_SLAVE_ADDRESS  0 // Set a value from 8 to 127 to act as a slave
 
 #endif // CONFIGURATION_ADV_H
diff --git a/Marlin/example_configurations/TAZ4/Configuration_adv.h b/Marlin/example_configurations/TAZ4/Configuration_adv.h
index 1417c803d..224de6415 100644
--- a/Marlin/example_configurations/TAZ4/Configuration_adv.h
+++ b/Marlin/example_configurations/TAZ4/Configuration_adv.h
@@ -803,6 +803,6 @@ const unsigned int dropsegments = 5; //everything with less than this number of
 // @section i2cbus
 
 //#define EXPERIMENTAL_I2CBUS
-#define I2C_SLAVE_ADDRESS  0 // Set non-zero to act as a slave
+#define I2C_SLAVE_ADDRESS  0 // Set a value from 8 to 127 to act as a slave
 
 #endif // CONFIGURATION_ADV_H
diff --git a/Marlin/example_configurations/WITBOX/Configuration_adv.h b/Marlin/example_configurations/WITBOX/Configuration_adv.h
index d26e2207b..452f5da81 100644
--- a/Marlin/example_configurations/WITBOX/Configuration_adv.h
+++ b/Marlin/example_configurations/WITBOX/Configuration_adv.h
@@ -795,6 +795,6 @@ const unsigned int dropsegments = 5; //everything with less than this number of
 // @section i2cbus
 
 //#define EXPERIMENTAL_I2CBUS
-#define I2C_SLAVE_ADDRESS  0 // Set non-zero to act as a slave
+#define I2C_SLAVE_ADDRESS  0 // Set a value from 8 to 127 to act as a slave
 
 #endif // CONFIGURATION_ADV_H
diff --git a/Marlin/example_configurations/delta/biv2.5/Configuration_adv.h b/Marlin/example_configurations/delta/biv2.5/Configuration_adv.h
index 828391a3f..61a4a3f2f 100644
--- a/Marlin/example_configurations/delta/biv2.5/Configuration_adv.h
+++ b/Marlin/example_configurations/delta/biv2.5/Configuration_adv.h
@@ -797,6 +797,6 @@ const unsigned int dropsegments = 5; //everything with less than this number of
 // @section i2cbus
 
 //#define EXPERIMENTAL_I2CBUS
-#define I2C_SLAVE_ADDRESS  0 // Set non-zero to act as a slave
+#define I2C_SLAVE_ADDRESS  0 // Set a value from 8 to 127 to act as a slave
 
 #endif // CONFIGURATION_ADV_H
diff --git a/Marlin/example_configurations/delta/generic/Configuration_adv.h b/Marlin/example_configurations/delta/generic/Configuration_adv.h
index 967a3e6b5..bbf712aab 100644
--- a/Marlin/example_configurations/delta/generic/Configuration_adv.h
+++ b/Marlin/example_configurations/delta/generic/Configuration_adv.h
@@ -797,6 +797,6 @@ const unsigned int dropsegments = 5; //everything with less than this number of
 // @section i2cbus
 
 //#define EXPERIMENTAL_I2CBUS
-#define I2C_SLAVE_ADDRESS  0 // Set non-zero to act as a slave
+#define I2C_SLAVE_ADDRESS  0 // Set a value from 8 to 127 to act as a slave
 
 #endif // CONFIGURATION_ADV_H
diff --git a/Marlin/example_configurations/delta/kossel_mini/Configuration_adv.h b/Marlin/example_configurations/delta/kossel_mini/Configuration_adv.h
index 64ea68fcd..cc51dc087 100644
--- a/Marlin/example_configurations/delta/kossel_mini/Configuration_adv.h
+++ b/Marlin/example_configurations/delta/kossel_mini/Configuration_adv.h
@@ -796,6 +796,6 @@ const unsigned int dropsegments = 5; //everything with less than this number of
 // @section i2cbus
 
 //#define EXPERIMENTAL_I2CBUS
-#define I2C_SLAVE_ADDRESS  0 // Set non-zero to act as a slave
+#define I2C_SLAVE_ADDRESS  0 // Set a value from 8 to 127 to act as a slave
 
 #endif // CONFIGURATION_ADV_H
diff --git a/Marlin/example_configurations/delta/kossel_pro/Configuration_adv.h b/Marlin/example_configurations/delta/kossel_pro/Configuration_adv.h
index 99fbcf08f..263245cac 100644
--- a/Marlin/example_configurations/delta/kossel_pro/Configuration_adv.h
+++ b/Marlin/example_configurations/delta/kossel_pro/Configuration_adv.h
@@ -801,6 +801,6 @@ const unsigned int dropsegments = 5; //everything with less than this number of
 // @section i2cbus
 
 //#define EXPERIMENTAL_I2CBUS
-#define I2C_SLAVE_ADDRESS  0 // Set non-zero to act as a slave
+#define I2C_SLAVE_ADDRESS  0 // Set a value from 8 to 127 to act as a slave
 
 #endif // CONFIGURATION_ADV_H
diff --git a/Marlin/example_configurations/delta/kossel_xl/Configuration_adv.h b/Marlin/example_configurations/delta/kossel_xl/Configuration_adv.h
index 0af7481f9..a4b6743f4 100644
--- a/Marlin/example_configurations/delta/kossel_xl/Configuration_adv.h
+++ b/Marlin/example_configurations/delta/kossel_xl/Configuration_adv.h
@@ -797,6 +797,6 @@ const unsigned int dropsegments = 5; //everything with less than this number of
 // @section i2cbus
 
 //#define EXPERIMENTAL_I2CBUS
-#define I2C_SLAVE_ADDRESS  0 // Set non-zero to act as a slave
+#define I2C_SLAVE_ADDRESS  0 // Set a value from 8 to 127 to act as a slave
 
 #endif // CONFIGURATION_ADV_H
diff --git a/Marlin/example_configurations/makibox/Configuration_adv.h b/Marlin/example_configurations/makibox/Configuration_adv.h
index 7715b71a3..2d5e62523 100644
--- a/Marlin/example_configurations/makibox/Configuration_adv.h
+++ b/Marlin/example_configurations/makibox/Configuration_adv.h
@@ -795,6 +795,6 @@ const unsigned int dropsegments = 5; //everything with less than this number of
 // @section i2cbus
 
 //#define EXPERIMENTAL_I2CBUS
-#define I2C_SLAVE_ADDRESS  0 // Set non-zero to act as a slave
+#define I2C_SLAVE_ADDRESS  0 // Set a value from 8 to 127 to act as a slave
 
 #endif // CONFIGURATION_ADV_H
diff --git a/Marlin/example_configurations/tvrrug/Round2/Configuration_adv.h b/Marlin/example_configurations/tvrrug/Round2/Configuration_adv.h
index 3cfe5860b..b3ee0a405 100644
--- a/Marlin/example_configurations/tvrrug/Round2/Configuration_adv.h
+++ b/Marlin/example_configurations/tvrrug/Round2/Configuration_adv.h
@@ -795,6 +795,6 @@ const unsigned int dropsegments = 5; //everything with less than this number of
 // @section i2cbus
 
 //#define EXPERIMENTAL_I2CBUS
-#define I2C_SLAVE_ADDRESS  0 // Set non-zero to act as a slave
+#define I2C_SLAVE_ADDRESS  0 // Set a value from 8 to 127 to act as a slave
 
 #endif // CONFIGURATION_ADV_H
diff --git a/Marlin/twibus.cpp b/Marlin/twibus.cpp
index bf17db3c2..11f205713 100644
--- a/Marlin/twibus.cpp
+++ b/Marlin/twibus.cpp
@@ -43,6 +43,11 @@ void TWIBus::reset() {
 }
 
 void TWIBus::address(const uint8_t adr) {
+  if (adr < 8 || adr > 127) {
+    SERIAL_ECHO_START;
+    SERIAL_ECHOLNPGM("Bad I2C address (8-127)");
+  }
+
   this->addr = adr;
 
   #if ENABLED(DEBUG_TWIBUS)