diff --git a/inst/cta/src/GCTAResponse.cpp b/inst/cta/src/GCTAResponse.cpp
index 05865cd..8fa3260 100644
--- a/inst/cta/src/GCTAResponse.cpp
+++ b/inst/cta/src/GCTAResponse.cpp
@@ -64,8 +64,7 @@
                                           " GEnergy&, GTime&, GObservation&)"
 #define G_NPRED             "GCTAResponse::npred(GSkyDir&, GEnergy&, GTime&,"\
                                                             " GObservation&)"
-#define G_MC            "GCTAResponse::mc(double&,GPhoton&,GPointing&,GRan&)"
-
+#define G_MC      "GCTAResponse::mc(double&, GPhoton&, GObservation&, GRan&)"
 #define G_IRF_RADIAL            "GCTAResponse::irf_radial(GEvent&, GSource&,"\
                                                             " GObservation&)"
 #define G_IRF_ELLIPTICAL    "GCTAResponse::irf_elliptical(GEvent&, GSource&,"\
@@ -471,6 +470,18 @@ GCTAEventAtom* GCTAResponse::mc(const double& area, const GPhoton& photon,
     // Compute limiting value
     double ulimite = effective_area / area;
 
+    // Warning if ulimite is larger than one
+    if (ulimite > 1.0) {
+        std::string msg = "Effective area "+
+                          gammalib::str(effective_area)+
+                          " cm2 is larger than simulation surface area "+
+                          gammalib::str(area)+
+                          " cm2 for photon energy "+
+                          gammalib::str(photon.energy().TeV())+
+                          " TeV. Simulations are inaccurate.";
+        gammalib::warning(G_MC, msg);
+    }
+
     // Continue only if event is detected
     if (ran.uniform() <= ulimite) {
 
@@ -1487,9 +1498,6 @@ double GCTAResponse::npred_radial(const GSource& source,
         GIntegral integral(&integrand);
         npred = integral.romb(rho_min, rho_max);
 
-        // Apply deadtime correction
-        npred *= obs.deadc(srcTime);
-
         // Compile option: Show integration results
         #if defined(G_DEBUG_NPRED_RADIAL)
         std::cout << "GCTAResponse::npred_radial:";
@@ -1650,9 +1658,6 @@ double GCTAResponse::npred_elliptical(const GSource& source,
         GIntegral integral(&integrand);
         npred = integral.romb(rho_min, rho_max);
 
-        // Apply deadtime correction
-        npred *= obs.deadc(srcTime);
-
         // Compile option: Show integration results
         #if defined(G_DEBUG_NPRED_ELLIPTICAL)
         std::cout << "GCTAResponse::npred_elliptical:";
@@ -1817,13 +1822,9 @@ double GCTAResponse::npred_diffuse(const GSource& source,
 
             // Integrate over theta
             GIntegral integral(&integrand);
-            //integral.eps(1.0e-4);
-            integral.eps(1.0e-5);
+            integral.eps(1.0e-4);
             npred = integral.romb(0.0, roi_psf_radius);
 
-            // Apply deadtime correction
-            npred *= obs.deadc(srcTime);
-
             // Compile option: Show integration results
             #if defined(G_DEBUG_NPRED_DIFFUSE)
             std::cout << "GCTAResponse::npred_diffuse:";