diff --git a/Detector/DetCRD/src/Tracker/TPC_ModularEndcap_o1_v01.cpp b/Detector/DetCRD/src/Tracker/TPC_ModularEndcap_o1_v01.cpp
index edd4bddb0c45f1d25276f72edce8c6749d439766..49df905f6cb3f566068ba8e866f4a89ed73f8e4f 100644
--- a/Detector/DetCRD/src/Tracker/TPC_ModularEndcap_o1_v01.cpp
+++ b/Detector/DetCRD/src/Tracker/TPC_ModularEndcap_o1_v01.cpp
@@ -90,6 +90,7 @@ static Ref_t create_element(Detector& theDetector, xml_h e, SensitiveDetector se
     const double rOuter             = theDetector.constant<double>("TPC_outer_radius") ;
     const double drInnerWall        = theDetector.constant<double>("TPC_dr_InnerWall");
     const double drOuterWall        = theDetector.constant<double>("TPC_dr_OuterWall");
+    const double drInnerServiceArea = theDetector.constant<double>("TPC_dr_InnerServiceArea");
     const double dz_Cathode         = theDetector.constant<double>("TPC_dz_Cathode");
     const double dz_Endplate        = theDetector.constant<double>("TPC_dz_Endplate");
     const double dz_Readout         = theDetector.constant<double>("TPC_dz_Readout");
@@ -510,8 +511,8 @@ static Ref_t create_element(Detector& theDetector, xml_h e, SensitiveDetector se
     tpcData->rMax  = rOuter;
     tpcData->innerWallThickness = drInnerWall;
     tpcData->outerWallThickness = drOuterWall;
-    tpcData->rMinReadout = rInner + drInnerWall;
-    tpcData->rMaxReadout = rInner + drInnerWall + tpcnumberOfPadRows*tpcpadheight;
+    tpcData->rMinReadout = rInner + drInnerWall + drInnerServiceArea;
+    tpcData->rMaxReadout = rInner + drInnerWall + drInnerServiceArea + tpcnumberOfPadRows*tpcpadheight;
     tpcData->maxRow = tpcnumberOfPadRows;
     tpcData->padHeight = tpcpadheight;
     tpcData->padWidth =  tpcpadwidth;
diff --git a/Detector/DetCRD/src/Tracker/TPC_Simple_o1_v01.cpp b/Detector/DetCRD/src/Tracker/TPC_Simple_o1_v01.cpp
index a137e03dd9ed6327ca1d19562edf24c7578c7c90..a8bb12ef6871e947f343fbe1a174bb95f486b2d5 100644
--- a/Detector/DetCRD/src/Tracker/TPC_Simple_o1_v01.cpp
+++ b/Detector/DetCRD/src/Tracker/TPC_Simple_o1_v01.cpp
@@ -90,6 +90,7 @@ static Ref_t create_element(Detector& theDetector, xml_h e, SensitiveDetector se
     const double rOuter             = theDetector.constant<double>("TPC_outer_radius") ;
     const double drInnerWall        = theDetector.constant<double>("TPC_dr_InnerWall");
     const double drOuterWall        = theDetector.constant<double>("TPC_dr_OuterWall");
+    const double drInnerServiceArea = theDetector.constant<double>("TPC_dr_InnerServiceArea");
     const double dz_Cathode         = theDetector.constant<double>("TPC_dz_Cathode");
     const double dz_Endplate        = theDetector.constant<double>("TPC_dz_Endplate");
     const double dz_Readout         = theDetector.constant<double>("TPC_dz_Readout");
@@ -454,8 +455,8 @@ static Ref_t create_element(Detector& theDetector, xml_h e, SensitiveDetector se
     tpcData->rMax  = rOuter;
     tpcData->innerWallThickness = drInnerWall;
     tpcData->outerWallThickness = drOuterWall;
-    tpcData->rMinReadout = rInner + drInnerWall;
-    tpcData->rMaxReadout = rInner + drInnerWall + tpcnumberOfPadRows*tpcpadheight;
+    tpcData->rMinReadout = rInner + drInnerWall + drInnerServiceArea;
+    tpcData->rMaxReadout = rInner + drInnerWall + drInnerServiceArea + tpcnumberOfPadRows*tpcpadheight;
     tpcData->maxRow = tpcnumberOfPadRows;
     tpcData->padHeight = tpcpadheight;
     tpcData->padWidth =  tpcpadwidth;