diff --git a/src/processor/processor_imu.cpp b/src/processor/processor_imu.cpp
index 5fc392a87dd7ad5328d56c3f8a5271b31391cf10..56d47d96e6e23737c76066f795f9aa9c591686cd 100644
--- a/src/processor/processor_imu.cpp
+++ b/src/processor/processor_imu.cpp
@@ -265,7 +265,7 @@ void ProcessorImu::bootstrap()
         case ParamsProcessorImu::BootstrapMethod::BOOTSTRAP_G:
         {
             // Implementation of G strategy. 
-            if (last_ptr_->getBuffer().size() > params_motion_Imu_->bootstrap_averaging_length) 
+            if (last_ptr_->getBuffer().size() - 1 > params_motion_Imu_->bootstrap_averaging_length) 
             {
                 // frames:
                 //   w: world global ( where g = [0,0,-9.806] );