diff --git a/src/hydro_source_TATB.cpp b/src/hydro_source_TATB.cpp
index 296dcb23..df09d646 100644
--- a/src/hydro_source_TATB.cpp
+++ b/src/hydro_source_TATB.cpp
@@ -383,8 +383,8 @@ double HydroSourceTATB::eta_rhob_right_factor(const double eta) const {
     double sigma_B_minus = DATA_.eta_rhob_width_2;
 
     // double norm        = 1./(sqrt(M_PI)*tau_source*sigma_B_plus);
-    double exp_arg_1 = (eta + eta_0_nB) / sigma_B_plus;
-    double exp_arg_2 = (eta + eta_0_nB) / sigma_B_minus;
+    double exp_arg_1 = (eta + eta_0_nB) / sigma_B_minus;
+    double exp_arg_2 = (eta + eta_0_nB) / sigma_B_plus;
 
     double res =
         Util::theta(eta + eta_0_nB) * std::exp(-exp_arg_1 * exp_arg_1 / 2.)