diff --git a/scripts/ci-defaults.sh b/scripts/ci-defaults.sh
index 616481251..65bd15873 100644
--- a/scripts/ci-defaults.sh
+++ b/scripts/ci-defaults.sh
@@ -1,13 +1,13 @@
-export CC=gcc
-export CXX=g++
-export FC=gfortran
-export BML_INTERNAL_BLAS=no
-export BML_MPI=no
-export BML_MPIEXEC_NUMPROCS_FLAG=-n
-export BML_MPIEXEC_NUMPROCS=4
-export BML_OPENMP=no
-export BML_VALGRIND=no
-export BML_SCALAPACK=no
-export BUILD_SHARED_LIBS=no
-export VERBOSE_MAKEFILE=yes
-export CMAKE_BUILD_TYPE=Debug
+export CC=${CC:-gcc}
+export CXX=${CXX:-g++}
+export FC=${FC:-gfortran}
+export BML_INTERNAL_BLAS=${BML_INTERNAL_BLAS:-no}
+export BML_MPI=${BML_MPI:-no}
+export BML_MPIEXEC_NUMPROCS_FLAG=${BML_MPIEXEC_NUMPROCS_FLAG:-'-n'}
+export BML_MPIEXEC_NUMPROCS=${BML_MPIEXEC_NUMPROCS:-4}
+export BML_OPENMP=${BML_OPENMP:-no}
+export BML_VALGRIND=${BML_VALGRIND:-no}
+export BML_SCALAPACK=${BML_SCALAPACK:-no}
+export BUILD_SHARED_LIBS=${BUILD_SHARED_LIBS:-no}
+export VERBOSE_MAKEFILE=${VERBOSE_MAKEFILE:-yes}
+export CMAKE_BUILD_TYPE=${CMAKE_BUILD_TYPE:-Debug}
diff --git a/scripts/ci-gcc-11-C-double-complex.sh b/scripts/ci-gcc-11-C-double-complex.sh
index 04b8dbe23..e5ed551f2 100755
--- a/scripts/ci-gcc-11-C-double-complex.sh
+++ b/scripts/ci-gcc-11-C-double-complex.sh
@@ -4,15 +4,15 @@ set -e -u -x
 
 basedir=$(readlink --canonicalize $(dirname $0)/..)
 
-[[ -f ${basedir}/scripts/ci-defaults.sh ]] && . ${basedir}/scripts/ci-defaults.sh
+export CC=${CC:-gcc-11}
+export CXX=${CXX:-g++-11}
+export FC=${FC:-gfortran-11}
+export BUILD_SHARED_LIBS=${BUILD_SHARED_LIBS:-no}
+export BML_OPENMP=${BML_OPENMP:-no}
+export BML_INTERNAL_BLAS=${BML_INTERNAL_BLAS:-no}
+export TESTING_EXTRA_ARGS=${TESTING_EXTRA_ARGS:-"-R C-.*-double_complex"}
+export BML_VALGRIND=${BML_VALGRIND:-yes}
 
-export CC=gcc-11
-export CXX=g++-11
-export FC=gfortran-11
-export BUILD_SHARED_LIBS=no
-export BML_OPENMP=no
-export BML_INTERNAL_BLAS=no
-export TESTING_EXTRA_ARGS="-R C-.*-double_complex"
-export BML_VALGRIND=yes
+[[ -f ${basedir}/scripts/ci-defaults.sh ]] && . ${basedir}/scripts/ci-defaults.sh
 
 ${basedir}/build.sh --debug testing
diff --git a/scripts/ci-gcc-11-C-double-real.sh b/scripts/ci-gcc-11-C-double-real.sh
index 2bb84cb27..f916a29ac 100755
--- a/scripts/ci-gcc-11-C-double-real.sh
+++ b/scripts/ci-gcc-11-C-double-real.sh
@@ -4,15 +4,15 @@ set -e -u -x
 
 basedir=$(readlink --canonicalize $(dirname $0)/..)
 
-[[ -f ${basedir}/scripts/ci-defaults.sh ]] && . ${basedir}/scripts/ci-defaults.sh
+export CC=${CC:-gcc-11}
+export CXX=${CXX:-g++-11}
+export FC=${FC:-gfortran-11}
+export BUILD_SHARED_LIBS=${BUILD_SHARED_LIBS:-no}
+export BML_OPENMP=${BML_OPENMP:-no}
+export BML_INTERNAL_BLAS=${BML_INTERNAL_BLAS:-no}
+export TESTING_EXTRA_ARGS=${TESTING_EXTRA_ARGS:-"-R C-.*-double_real"}
+export BML_VALGRIND=${BML_VALGRIND:-yes}
 
-export CC=gcc-11
-export CXX=g++-11
-export FC=gfortran-11
-export BUILD_SHARED_LIBS=no
-export BML_OPENMP=no
-export BML_INTERNAL_BLAS=no
-export TESTING_EXTRA_ARGS="-R C-.*-double_real"
-export BML_VALGRIND=yes
+[[ -f ${basedir}/scripts/ci-defaults.sh ]] && . ${basedir}/scripts/ci-defaults.sh
 
 ${basedir}/build.sh --debug testing
diff --git a/scripts/ci-gcc-11-C-single-complex.sh b/scripts/ci-gcc-11-C-single-complex.sh
index a7da7ad58..1568abd68 100755
--- a/scripts/ci-gcc-11-C-single-complex.sh
+++ b/scripts/ci-gcc-11-C-single-complex.sh
@@ -4,15 +4,15 @@ set -e -u -x
 
 basedir=$(readlink --canonicalize $(dirname $0)/..)
 
-[[ -f ${basedir}/scripts/ci-defaults.sh ]] && . ${basedir}/scripts/ci-defaults.sh
+export CC=${CC:-gcc-11}
+export CXX=${CXX:-g++-11}
+export FC=${FC:-gfortran-11}
+export BUILD_SHARED_LIBS=${BUILD_SHARED_LIBS:-no}
+export BML_OPENMP=${BML_OPENMP:-no}
+export BML_INTERNAL_BLAS=${BML_INTERNAL_BLAS:-no}
+export TESTING_EXTRA_ARGS=${TESTING_EXTRA_ARGS:-"-R C-.*-single_complex"}
+export BML_VALGRIND=${BML_VALGRIND:-yes}
 
-export CC=gcc-11
-export CXX=g++-11
-export FC=gfortran-11
-export BUILD_SHARED_LIBS=no
-export BML_OPENMP=no
-export BML_INTERNAL_BLAS=no
-export TESTING_EXTRA_ARGS="-R C-.*-single_complex"
-export BML_VALGRIND=yes
+[[ -f ${basedir}/scripts/ci-defaults.sh ]] && . ${basedir}/scripts/ci-defaults.sh
 
 ${basedir}/build.sh --debug testing
diff --git a/scripts/ci-gcc-11-C-single-real.sh b/scripts/ci-gcc-11-C-single-real.sh
index a85690161..8f7e36fd5 100755
--- a/scripts/ci-gcc-11-C-single-real.sh
+++ b/scripts/ci-gcc-11-C-single-real.sh
@@ -4,15 +4,15 @@ set -e -u -x
 
 basedir=$(readlink --canonicalize $(dirname $0)/..)
 
-[[ -f ${basedir}/scripts/ci-defaults.sh ]] && . ${basedir}/scripts/ci-defaults.sh
+export CC=${CC:-gcc-11}
+export CXX=${CXX:-g++-11}
+export FC=${FC:-gfortran-11}
+export BUILD_SHARED_LIBS=${BUILD_SHARED_LIBS:-no}
+export BML_OPENMP=${BML_OPENMP:-no}
+export BML_INTERNAL_BLAS=${BML_INTERNAL_BLAS:-no}
+export TESTING_EXTRA_ARGS=${TESTING_EXTRA_ARGS:-"-R C-.*-single_real"}
+export BML_VALGRIND=${BML_VALGRIND:-yes}
 
-export CC=gcc-11
-export CXX=g++-11
-export FC=gfortran-11
-export BUILD_SHARED_LIBS=no
-export BML_OPENMP=no
-export BML_INTERNAL_BLAS=no
-export TESTING_EXTRA_ARGS="-R C-.*-single_real"
-export BML_VALGRIND=yes
+[[ -f ${basedir}/scripts/ci-defaults.sh ]] && . ${basedir}/scripts/ci-defaults.sh
 
 ${basedir}/build.sh --debug testing