diff --git a/src/processor/processor_odom_icp.cpp b/src/processor/processor_odom_icp.cpp
index 0cdbe27ec52f9bbd710793f8909d3d70255dd81c..4ec5e9adb4de8d885f00ae012e0565e0590e8781 100644
--- a/src/processor/processor_odom_icp.cpp
+++ b/src/processor/processor_odom_icp.cpp
@@ -236,7 +236,7 @@ void ProcessorOdomIcp::advanceDerived()
 
     // overwrite last frame's state
 
-    Isometry2d   w_T_ro = Translation2d(origin_ptr_->getFrame()->getState().at("P")) * Rotation2Dd(origin_ptr_->getFrame()->getState().at("O")(0));
+    Isometry2d   w_T_ro = Translation2d(origin_ptr_->getFrame()->getState().at('P')) * Rotation2Dd(origin_ptr_->getFrame()->getState().at('O')(0));
     Isometry2d  ro_T_so = Translation2d(origin_ptr_->getSensorP()->getState())       * Rotation2Dd(origin_ptr_->getSensorO()->getState()(0));
     Isometry2d& ri_T_si = ro_T_so; // A reference just to have nice names without computing overhead
 
diff --git a/src/processor/processor_tracker_feature_polyline_2d.cpp b/src/processor/processor_tracker_feature_polyline_2d.cpp
index fefda45e831f4b454a63960d7b4f8736cc5dad26..fc7ef54669b0bfec3fee40c3e1477d214660bedc 100644
--- a/src/processor/processor_tracker_feature_polyline_2d.cpp
+++ b/src/processor/processor_tracker_feature_polyline_2d.cpp
@@ -1310,8 +1310,8 @@ void ProcessorTrackerFeaturePolyline2d::computeTransformations()
     Eigen::Matrix2d R_world_robot_last     = Eigen::Rotation2Dd(vehicle_pose_last(2)).matrix();
 
     // robot_sensor (to be computed once if extrinsics are fixed and not dynamic)
-    if (getSensor()->isStateBlockDynamic("P") ||
-        getSensor()->isStateBlockDynamic("O") ||
+    if (getSensor()->isStateBlockDynamic('P') ||
+        getSensor()->isStateBlockDynamic('O') ||
         !getSensor()->getP()->isFixed() ||
         !getSensor()->getO()->isFixed() ||
         !extrinsics_transformation_computed_)