diff --git a/regtest/basic/rt13-lepton/plumed.dat b/regtest/basic/rt13-lepton/plumed.dat
index 99f6ece69bb250dbb911947d801e2ae77c7b1cf5..2e3629037477fdce2505776a440e14de88beb645 100644
--- a/regtest/basic/rt13-lepton/plumed.dat
+++ b/regtest/basic/rt13-lepton/plumed.dat
@@ -9,7 +9,7 @@ cc1: MATHEVAL ARG=t1,t2,t3 FUNC=x^2+y+0*z+1 PERIODIC=NO
 cc2: MATHEVAL ARG=t1,t2,t3 FUNC=0*x^3+0*y^3+0*z^3 PERIODIC=NO
 cc3: MATHEVAL ARG=t1,t2 FUNC=x^2+y^2 PERIODIC=NO
 
-all: MATHEVAL ARG=t1,t2,t3,cc1,cc2,cc3 VAR=a1,a2,a3,a4,a5,a6 FUNC={ (a1+a2+a3+a4+a5+a6) / 6.0 } PERIODIC=NO
+all: CUSTOM ARG=t1,t2,t3,cc1,cc2,cc3 VAR=a1,a2,a3,a4,a5,a6 FUNC={ (a1+a2+a3+a4+a5+a6) / 6.0 } PERIODIC=NO
 
 RESTRAINT ARG=all AT=0 SLOPE=1.0
 
diff --git a/regtest/basic/rt20b-lepton/plumed.dat b/regtest/basic/rt20b-lepton/plumed.dat
index 61dfd90164ae733af451d2dc2b6084ee3a12d407..463e8d3dbd975e4fba64264b38623db348c29b09 100644
--- a/regtest/basic/rt20b-lepton/plumed.dat
+++ b/regtest/basic/rt20b-lepton/plumed.dat
@@ -1,5 +1,5 @@
 c:   COORDINATION GROUPA=1 GROUPB=2 SWITCH={MATHEVAL R_0=1.3 D_MAX=2.6 FUNC=1/(1+x^6) NOSTRETCH}
-cs:  COORDINATION GROUPA=1 GROUPB=2 SWITCH={MATHEVAL R_0=1.3 D_MAX=2.6 FUNC=1/(1+x^6)}
+cs:  COORDINATION GROUPA=1 GROUPB=2 SWITCH={CUSTOM R_0=1.3 D_MAX=2.6 FUNC=1/(1+x^6)}
 
 PRINT ...
   ARG=c,cs