diff --git a/app/src/processing/app/SerialPlotter.java b/app/src/processing/app/SerialPlotter.java
index 336cbd43e7e..b234a3e4d6c 100644
--- a/app/src/processing/app/SerialPlotter.java
+++ b/app/src/processing/app/SerialPlotter.java
@@ -289,6 +289,10 @@ public void message(final String s) {
       messageBuffer.delete(0, linebreak + 1);
 
       line = line.trim();
+      if (line.length() == 0) {
+        // the line only contained trimmable characters
+        continue;
+      }
       String[] parts = line.split("[, \t]+");
       if(parts.length == 0) {
         continue;