diff --git a/regtest/basic/rt28/plumed.dat b/regtest/basic/rt28/plumed.dat
index a129628254bff6767b068653f966c03765eb8aa5..fe24a8367a0b6b24386b4b47bda7155d9afb561a 100644
--- a/regtest/basic/rt28/plumed.dat
+++ b/regtest/basic/rt28/plumed.dat
@@ -31,7 +31,7 @@ LABEL=c
 
 PRINT ...
   ARG=a,b,c.contact1,c.contact5
-  FILE=COLVAR
+  FILE=colvar
 ... PRINT
 
 DUMPDERIVATIVES ARG=a,b FILE=deriv FMT=%8.6f