diff --git a/pyrelacs/dataio/circbuffer.py b/pyrelacs/dataio/circbuffer.py
index 2e1fa40..30924cb 100644
--- a/pyrelacs/dataio/circbuffer.py
+++ b/pyrelacs/dataio/circbuffer.py
@@ -9,7 +9,7 @@ class CircBuffer:
         self,
         size: int,
         channels: int = 1,
-        samplerate: int = 40_000,
+        samplerate: float = 40_000.0,
         mutex: QMutex = QMutex(),
     ):
         self.__size = size