diff --git a/src/interval.cpp b/src/interval.cpp
index 3125c92..8f5546d 100644
--- a/src/interval.cpp
+++ b/src/interval.cpp
@@ -28,7 +28,7 @@ bool Interval::expired()
             // periodic mode
             if ((millis() - _timefrom) >= _timeout) {
                 result = true;
-                _timefrom = millis();
+                _timefrom += _timeout; // more precise periodic timing
             }
         } else {
             // compatibility mode