diff --git a/.circleci/config.yml b/.circleci/config.yml
index bdd90443..805611eb 100644
--- a/.circleci/config.yml
+++ b/.circleci/config.yml
@@ -6,7 +6,7 @@ version: 2.1
 parameters:
     tools-cache-version:
         type: string
-        default: "v6"
+        default: "v7"
 
 # default execution env.s
 executors:
diff --git a/scripts/build-toolchains.sh b/scripts/build-toolchains.sh
index ec2920a2..f4d20849 100755
--- a/scripts/build-toolchains.sh
+++ b/scripts/build-toolchains.sh
@@ -18,11 +18,12 @@ usage() {
     echo "   ec2fast: if set, pulls in a pre-compiled RISC-V toolchain for an EC2 manager instance"
     echo ""
     echo "Options"
-    echo "   --prefix PREFIX : Install destination. If unset, defaults to $(pwd)/riscv-tools-install"
-    echo "                     or $(pwd)/esp-tools-install"
-    echo "   --ignore-qemu   : Ignore installing QEMU"
-    echo "   --arch -a       : Architecture (e.g., rv64gc)"
-    echo "   --help -h       : Display this message"
+    echo "   --prefix PREFIX       : Install destination. If unset, defaults to $(pwd)/riscv-tools-install"
+    echo "                           or $(pwd)/esp-tools-install"
+    echo "   --ignore-qemu         : Ignore installing QEMU"
+    echo "   --clean-after-install : Run make clean in calls to module_make and module_build"
+    echo "   --arch -a             : Architecture (e.g., rv64gc)"
+    echo "   --help -h             : Display this message"
     exit "$1"
 }
 
@@ -37,6 +38,7 @@ die() {
 TOOLCHAIN="riscv-tools"
 EC2FASTINSTALL="false"
 IGNOREQEMU=""
+CLEANAFTERINSTALL=""
 RISCV=""
 ARCH=""
 
@@ -51,9 +53,11 @@ do
             RISCV=$(realpath $1) ;;
         --ignore-qemu )
             IGNOREQEMU="true" ;;
-	-a | --arch )
-	    shift
-	    ARCH=$1 ;;
+        -a | --arch )
+            shift
+            ARCH=$1 ;;
+        --clean-after-install )
+            CLEANAFTERINSTALL="true" ;;
         riscv-tools | esp-tools)
             TOOLCHAIN=$1 ;;
         ec2fast )
diff --git a/scripts/build-util.sh b/scripts/build-util.sh
index 892b274d..1af11aee 100644
--- a/scripts/build-util.sh
+++ b/scripts/build-util.sh
@@ -49,6 +49,9 @@ module_make() ( # <submodule> <target..>
     cd "${SRCDIR}/${1}/build"
     shift
     "${MAKE}" "$@" | tee "build-${1:-make}.log"
+    if [ -n "$CLEANAFTERINSTALL" ] ; then
+      "${MAKE}" clean  # get rid of intermediate files
+    fi
 )
 
 module_build() ( # <submodule> [configure-arg..]
@@ -81,6 +84,9 @@ module_build() ( # <submodule> [configure-arg..]
         "${MAKE}"
         echo "==>  Installing ${name}"
         "${MAKE}" install
+        if [ -n "$CLEANAFTERINSTALL" ] ; then
+          "${MAKE}" clean  # get rid of intermediate files
+        fi
     } 2>&1 | tee build.log
 )