diff --git a/pyqtgraph/multiprocess/processes.py b/pyqtgraph/multiprocess/processes.py
index 24fdebf2..33ac85c5 100644
--- a/pyqtgraph/multiprocess/processes.py
+++ b/pyqtgraph/multiprocess/processes.py
@@ -489,12 +489,12 @@ class FileForwarder(threading.Thread):
             while not self.finish.is_set():
                 line = self.input.readline()
                 with self.lock:
-                    cprint.cout(self.color, line, -1)
+                    cprint.cout(self.color, line.decode('utf8'), -1)
         elif self.output == 'stderr' and self.color is not False:
             while not self.finish.is_set():
                 line = self.input.readline()
                 with self.lock:
-                    cprint.cerr(self.color, line, -1)
+                    cprint.cerr(self.color, line.decode('utf8'), -1)
         else:
             if isinstance(self.output, str):
                 self.output = getattr(sys, self.output)