diff --git a/src/paper_thinstrip_full/thinstrip_full_chns_monolithic.hh b/src/paper_thinstrip_full/thinstrip_full_chns_monolithic.hh
index af534dbef695c3b2b842931687af8d0c427bda8c..54f8d683f1acd39fb3b6a1f2d0dd117e1f4fce96 100644
--- a/src/paper_thinstrip_full/thinstrip_full_chns_monolithic.hh
+++ b/src/paper_thinstrip_full/thinstrip_full_chns_monolithic.hh
@@ -142,7 +142,7 @@ public:
           + (pf_c*(chns.u-param.phys.uAst)*chns.div_v                            //TODO v or vOld
               + (chns.u-param.phys.uAst)*(chns.gradpf*chns.v)
               + pf_c*(chns.gradu*chns.v)                        )*chns.basis.phi[i]
-          - pf_c
+          - pf_c_reg_Old*param.ionSource*source*chns.basis.phi[i]
           ));
       } // for i