diff --git a/src/processor/processor_imu.cpp b/src/processor/processor_imu.cpp
index 11fc86b1d5f016d0f4021392c0cae1b309ef67c5..fea5b04d63af0f827865bd646ec88150d5b1fae7 100644
--- a/src/processor/processor_imu.cpp
+++ b/src/processor/processor_imu.cpp
@@ -49,7 +49,7 @@ void ProcessorImu::preProcess()
 bool ProcessorImu::voteForKeyFrame() const
 {
     // time span
-    if (getBuffer().back().ts_ - getBuffer().front().ts_ > params_motion_Imu_->max_time_span - params_motion_Imu_->time_tolerance)
+    if (getBuffer().back().ts_ - getBuffer().front().ts_ >= params_motion_Imu_->max_time_span - Constants::EPS)
     {
         WOLF_DEBUG( "PM: vote: time span" );
         return true;