diff --git a/SDL/EndcapGeometry.cc b/SDL/EndcapGeometry.cc
index b5cf8a3f..813ae229 100644
--- a/SDL/EndcapGeometry.cc
+++ b/SDL/EndcapGeometry.cc
@@ -22,7 +22,7 @@ SDL::EndcapGeometry::EndcapGeometry(std::string filename, unsigned int sizef)
 SDL::EndcapGeometry::~EndcapGeometry() {}
 
 void SDL::EndcapGeometry::load(std::string filename) {
-  sls_.clear();
+  dxdy_slope_.clear();
   centroid_phis_.clear();
 
   std::ifstream ifile(filename);
@@ -31,11 +31,13 @@ void SDL::EndcapGeometry::load(std::string filename) {
   while (std::getline(ifile, line)) {
     std::istringstream ss(line);
     unsigned int detid;
-    float sl, cp;
+    float dxdy_slope, centroid_phi;
 
-    if (ss >> detid >> sl >> cp) {
-      sls_[detid] = sl;
-      centroid_phis_[detid] = cp;
+    if (ss >> detid >> dxdy_slope >> centroid_phi) {
+      dxdy_slope_[detid] = dxdy_slope;
+      centroid_phis_[detid] = centroid_phi;
+    } else {
+      throw std::runtime_error("Failed to parse line: " + line);
     }
   }
 
@@ -80,4 +82,4 @@ void SDL::EndcapGeometry::fillGeoMapArraysExplicit() {
   alpaka::wait(queue);
 }
 
-float SDL::EndcapGeometry::getSlopeLower(unsigned int detid) { return sls_[detid]; }
\ No newline at end of file
+float SDL::EndcapGeometry::getdxdy_slope(unsigned int detid) { return dxdy_slope_[detid]; }
\ No newline at end of file
diff --git a/SDL/EndcapGeometry.h b/SDL/EndcapGeometry.h
index f0d9957b..4c51a8ea 100644
--- a/SDL/EndcapGeometry.h
+++ b/SDL/EndcapGeometry.h
@@ -7,13 +7,14 @@
 #include <sstream>
 #include <string>
 #include <vector>
+#include <stdexcept>
 
 #include "Constants.h"
 
 namespace SDL {
   class EndcapGeometry {
   private:
-    std::map<unsigned int, float> sls_;            // lower slope
+    std::map<unsigned int, float> dxdy_slope_;     // dx/dy slope
     std::map<unsigned int, float> centroid_phis_;  // centroid phi
 
   public:
@@ -30,9 +31,7 @@ namespace SDL {
 
     void fillGeoMapArraysExplicit();
     void CreateGeoMapArraysExplicit();
-    float getAverageR2(unsigned int detid);
-    float getYInterceptLower(unsigned int detid);
-    float getSlopeLower(unsigned int detid);
+    float getdxdy_slope(unsigned int detid);
   };
   void freeEndcap();
   extern EndcapGeometry* endcapGeometry;
diff --git a/SDL/ModuleMethods.h b/SDL/ModuleMethods.h
index ffe27c82..70b58796 100644
--- a/SDL/ModuleMethods.h
+++ b/SDL/ModuleMethods.h
@@ -374,7 +374,7 @@ namespace SDL {
           host_isAnchor[index] = false;
         }
 
-        host_slopes[index] = (subdet == Endcap) ? endcapGeometry->getSlopeLower(detId) : tiltedGeometry.getSlope(detId);
+        host_slopes[index] = (subdet == Endcap) ? endcapGeometry->getdxdy_slope(detId) : tiltedGeometry.getSlope(detId);
         host_drdzs[index] = (subdet == Barrel) ? tiltedGeometry.getDrDz(detId) : 0;
       }
 
diff --git a/SDL/TiltedGeometry.cc b/SDL/TiltedGeometry.cc
index 658225cd..e9c564cc 100644
--- a/SDL/TiltedGeometry.cc
+++ b/SDL/TiltedGeometry.cc
@@ -23,10 +23,12 @@ void SDL::TiltedGeometry::load(std::string filename) {
 
     std::stringstream ss(line);
 
-    ss >> detid >> drdz >> slope;
-
-    drdzs_[detid] = drdz;
-    slopes_[detid] = slope;
+    if (ss >> detid >> drdz >> slope) {
+      drdzs_[detid] = drdz;
+      slopes_[detid] = slope;
+    } else {
+      throw std::runtime_error("Failed to parse line: " + line);
+    }
   }
 }