diff --git a/Marlin/Configuration.h b/Marlin/Configuration.h
index 41e1ed7ed9b6eb2e974af43ed05ef8f27bce5dfa..afcd9134cbd7b6c5b49421cd7f391ad7389e41d7 100644
--- a/Marlin/Configuration.h
+++ b/Marlin/Configuration.h
@@ -118,6 +118,7 @@ Here are some standard links for getting your machine calibrated:
 // 1010 is Pt1000 with 1k pullup (non standard)
 // 147 is Pt100 with 4k7 pullup
 // 110 is Pt100 with 1k pullup (non standard)
+// 999 is a Dummy Table. It will ALWAYS read 25C.. Use it for Testing or Development purposes. NEVER for production machine.
 
 #define TEMP_SENSOR_0 -1
 #define TEMP_SENSOR_1 -1
diff --git a/Marlin/thermistortables.h b/Marlin/thermistortables.h
index 599d0d05cc3e7a6aef1039e637e6df63e061ce24..aa1019b0ab52b28561b119ad7e71911308be1a33 100644
--- a/Marlin/thermistortables.h
+++ b/Marlin/thermistortables.h
@@ -1095,6 +1095,16 @@ const short temptable_1047[][2] PROGMEM = {
 };
 #endif
 
+#if (THERMISTORHEATER_0 == 999) || (THERMISTORHEATER_1 == 999) || (THERMISTORHEATER_2 == 999) || (THERMISTORHEATER_3 == 999) || (THERMISTORBED == 999) //User defined table
+// Dummy Thermistor table.. It will ALWAYS read 25C.
+const short temptable_999[][2] PROGMEM = {
+   {1*OVERSAMPLENR, 25},
+   {1023*OVERSAMPLENR, 25}
+};
+#endif
+
+
+
 #define _TT_NAME(_N) temptable_ ## _N
 #define TT_NAME(_N) _TT_NAME(_N)