diff --git a/monitor/system.cpp b/monitor/system.cpp
index 050913e..aff3bdc 100644
--- a/monitor/system.cpp
+++ b/monitor/system.cpp
@@ -1,5 +1,5 @@
 /**
- * Copyright © 2021 IBM Corporation
+ * Copyright © 2022 IBM Corporation
  *
  * Licensed under the Apache License, Version 2.0 (the "License");
  * you may not use this file except in compliance with the License.
@@ -483,11 +483,20 @@
             values["present"] = fan->present();
             values["functional"] = sensor->functional();
             values["tach"] = sensor->getInput();
+
             if (sensor->hasTarget())
             {
                 values["target"] = sensor->getTarget();
             }
 
+            // convert between string/json to remove newlines
+            values["prev_tachs"] = json(sensor->getPrevTach()).dump();
+
+            if (sensor->hasTarget())
+            {
+                values["prev_targets"] = json(sensor->getPrevTarget()).dump();
+            }
+
             data["sensors"][sensor->name()] = values;
         }
     }