diff --git a/cmake/scripts/config.csh.in b/cmake/scripts/config.csh.in
index 86da852bd4577b2238a699d018ab7ba8414f9812..6d0b1f7aabf40acc9489e6aef65fcda1f3903dc2 100644
--- a/cmake/scripts/config.csh.in
+++ b/cmake/scripts/config.csh.in
@@ -30,7 +30,6 @@ if ( "$same_system" == "1" ) then
 	setenv VMCWORKDIR "@VMCWORKDIR@"
 	setenv FAIRLIBDIR "@FAIRLIBDIR@"
 	setenv PYTHONPATH "@MY_PYTHONPATH@"
-	setenv OMP_NUM_THREADS @OMP_NUM_THREADS@
 	if (! $?OMP_NUM_THREADS) then
 		setenv OMP_NUM_THREADS @OMP_NUM_THREADS@
 	else
diff --git a/cmake/scripts/config.sh.in b/cmake/scripts/config.sh.in
index 0097d168f253a518ab8a876ea7ca1293a1d272dd..4b939d17ad8f9eb520d66a0240b2d3796ca3ad8c 100644
--- a/cmake/scripts/config.sh.in
+++ b/cmake/scripts/config.sh.in
@@ -29,7 +29,7 @@ if [ $same_system -eq 1 ]; then
 	export VMCWORKDIR="@VMCWORKDIR@"
 	export FAIRLIBDIR="@FAIRLIBDIR@"
 	export PYTHONPATH="@MY_PYTHONPATH@"
-	if [[ -z "${OMP_NUM_THREADS}" ]]; then
+	if [[ -z $OMP_NUM_THREADS ]]; then
 		export OMP_NUM_THREADS=@OMP_NUM_THREADS@
 	fi
 
diff --git a/cmake/scripts/root_macro.sh.in b/cmake/scripts/root_macro.sh.in
index 9082e424c6950045e21b47ca1e13164a2627fe55..f22d220bc8b775fd986c55230039d2223cfabbb7 100644
--- a/cmake/scripts/root_macro.sh.in
+++ b/cmake/scripts/root_macro.sh.in
@@ -19,7 +19,7 @@ export VMCWORKDIR=@VMCWORKDIR@
 export Geant4VMC_MACRO_DIR=@Geant4VMC_MACRO_DIR@
 export USE_VGM=1
 export BOOST=@Boost_Avail@
-if [[ -z "${OMP_NUM_THREADS}" ]]; then
+if [[ -z $OMP_NUM_THREADS ]]; then
   export OMP_NUM_THREADS=@OMP_NUM_THREADS@
 fi