diff --git a/scripts/chk_shellscripts/ignore.txt b/scripts/chk_shellscripts/ignore.txt
index 220ed9f57..188efb0ab 100644
--- a/scripts/chk_shellscripts/ignore.txt
+++ b/scripts/chk_shellscripts/ignore.txt
@@ -1,12 +1,5 @@
 ./test/docsCodeStyle.sh
 ./test/cmdlineTests.sh
-./test/externalTests.sh
-./test/externalTests/common.sh
-./test/externalTests/gnosis.sh
-./test/externalTests/zeppelin.sh
-./test/externalTests/colony.sh
-./test/externalTests/solc-js/solc-js.sh
-./scripts/common.sh
 ./scripts/isoltest.sh
 ./scripts/get_version.sh
 ./scripts/soltest.sh
diff --git a/scripts/common.sh b/scripts/common.sh
index fbb730241..3518a21aa 100644
--- a/scripts/common.sh
+++ b/scripts/common.sh
@@ -1,3 +1,4 @@
+#!/usr/bin/env bash
 # ------------------------------------------------------------------------------
 # vim:ts=4:et
 # This file is part of solidity.
@@ -37,21 +38,21 @@ safe_kill()
     local n=1
 
     # only proceed if $PID does exist
-    kill -0 $PID 2>/dev/null || return
+    kill -0 "$PID" 2>/dev/null || return
 
     echo "Sending SIGTERM to ${NAME} (${PID}) ..."
-    kill $PID
+    kill "$PID"
 
     # wait until process terminated gracefully
-    while kill -0 $PID 2>/dev/null && [[ $n -le 4 ]]; do
+    while kill -0 "$PID" 2>/dev/null && [[ $n -le 4 ]]; do
         echo "Waiting ($n) ..."
         sleep 1
-        n=$[n + 1]
+        n=$((n + 1))
     done
 
     # process still alive? then hard-kill
-    if kill -0 $PID 2>/dev/null; then
+    if kill -0 "$PID" 2>/dev/null; then
         echo "Sending SIGKILL to ${NAME} (${PID}) ..."
-        kill -9 $PID
+        kill -9 "$PID"
     fi
 }
diff --git a/test/externalTests.sh b/test/externalTests.sh
index 7bf3eb76b..e53f9925a 100755
--- a/test/externalTests.sh
+++ b/test/externalTests.sh
@@ -42,10 +42,10 @@ source test/externalTests/common.sh
 
 printTask "Running external tests..."
 
-$REPO_ROOT/externalTests/zeppelin.sh "$SOLJSON"
-$REPO_ROOT/externalTests/gnosis.sh "$SOLJSON"
-$REPO_ROOT/externalTests/colony.sh "$SOLJSON"
-$REPO_ROOT/externalTests/ens.sh "$SOLJSON"
+"$REPO_ROOT/externalTests/zeppelin.sh" "$SOLJSON"
+"$REPO_ROOT/externalTests/gnosis.sh" "$SOLJSON"
+"$REPO_ROOT/externalTests/colony.sh" "$SOLJSON"
+"$REPO_ROOT/externalTests/ens.sh" "$SOLJSON"
 
 # Disabled temporarily as it needs to be updated to latest Truffle first.
 #test_truffle Gnosis https://github.com/axic/pm-contracts.git solidity-050
diff --git a/test/externalTests/colony.sh b/test/externalTests/colony.sh
index 6a246b2b9..349cabf2a 100755
--- a/test/externalTests/colony.sh
+++ b/test/externalTests/colony.sh
@@ -31,18 +31,17 @@ function test_fn { yarn run test:contracts; }
 function colony_test
 {
     OPTIMIZER_LEVEL=3
-    FORCE_ABIv2=false
     CONFIG="truffle.js"
 
-    truffle_setup https://github.com/solidity-external-tests/colonyNetwork.git develop_070
-    run_install install_fn
+    truffle_setup "$SOLJSON" https://github.com/solidity-external-tests/colonyNetwork.git develop_070
+    run_install "$SOLJSON" install_fn
 
     cd lib
     rm -Rf dappsys
     git clone https://github.com/solidity-external-tests/dappsys-monolithic.git -b master_060 dappsys
     cd ..
 
-    truffle_run_test compile_fn test_fn
+    truffle_run_test "$SOLJSON" compile_fn test_fn "NO-FORCE-ABI-V2"
 }
 
 external_test ColonyNetworks colony_test
diff --git a/test/externalTests/common.sh b/test/externalTests/common.sh
index d56912a85..ad36a5ff4 100644
--- a/test/externalTests/common.sh
+++ b/test/externalTests/common.sh
@@ -40,9 +40,10 @@ function verify_version_input
 
 function setup
 {
-    local branch="$1"
+    local soljson="$1"
+    local branch="$2"
 
-    setup_solcjs "$DIR" "$SOLJSON" "$branch" "solc"
+    setup_solcjs "$DIR" "$soljson" "$branch" "solc"
     cd solc
 }
 
@@ -80,7 +81,7 @@ function download_project
     printLog "Cloning $branch of $repo..."
     git clone --depth 1 "$repo" -b "$branch" "$dir/ext"
     cd ext
-    echo "Current commit hash: `git rev-parse HEAD`"
+    echo "Current commit hash: $(git rev-parse HEAD)"
 }
 
 function force_truffle_version
@@ -92,10 +93,11 @@ function force_truffle_version
 
 function truffle_setup
 {
-    local repo="$1"
-    local branch="$2"
+    local soljson="$1"
+    local repo="$2"
+    local branch="$3"
 
-    setup_solcjs "$DIR" "$SOLJSON" "master" "solc"
+    setup_solcjs "$DIR" "$soljson" "master" "solc"
     download_project "$repo" "$branch" "$DIR"
 }
 
@@ -207,11 +209,12 @@ function clean
 
 function run_install
 {
-    local init_fn="$1"
+    local soljson="$1"
+    local init_fn="$2"
     printLog "Running install function..."
 
     replace_version_pragmas
-    force_solc "$CONFIG" "$DIR" "$SOLJSON"
+    force_solc "$CONFIG" "$DIR" "$soljson"
 
     $init_fn
 }
@@ -232,11 +235,15 @@ function run_test
 
 function truffle_run_test
 {
-    local compile_fn="$1"
-    local test_fn="$2"
+    local soljson="$1"
+    local compile_fn="$2"
+    local test_fn="$3"
+    local force_abi_v2_flag="$4"
+
+    test "$force_abi_v2_flag" = "FORCE-ABI-V2" || test "$force_abi_v2_flag" = "NO-FORCE-ABI-V2"
 
     replace_version_pragmas
-    force_solc "$CONFIG" "$DIR" "$SOLJSON"
+    force_solc "$CONFIG" "$DIR" "$soljson"
 
     printLog "Checking optimizer level..."
     if [ -z "$OPTIMIZER_LEVEL" ]; then
@@ -258,7 +265,7 @@ function truffle_run_test
         clean
         force_solc_settings "$CONFIG" "$optimize" "istanbul"
         # Force abi coder v2 in the last step. Has to be the last because code is modified.
-        if [ "$FORCE_ABIv2" = true ]; then
+        if [ "$force_abi_v2_flag" = "FORCE-ABI-V2" ]; then
             [[ "$optimize" =~ yul ]] && force_abi_v2
         fi
 
diff --git a/test/externalTests/ens.sh b/test/externalTests/ens.sh
index 52cccdb56..99f4b8971 100755
--- a/test/externalTests/ens.sh
+++ b/test/externalTests/ens.sh
@@ -18,9 +18,7 @@
 #
 # (c) 2019 solidity contributors.
 #------------------------------------------------------------------------------
-# shellcheck disable=SC1091
 source scripts/common.sh
-# shellcheck disable=SC1091
 source test/externalTests/common.sh
 
 verify_input "$1"
@@ -35,14 +33,14 @@ function ens_test
     export OPTIMIZER_LEVEL=1
     export CONFIG="truffle-config.js"
 
-    truffle_setup https://github.com/solidity-external-tests/ens.git upgrade-0.8.0
+    truffle_setup "$SOLJSON" https://github.com/solidity-external-tests/ens.git upgrade-0.8.0
 
     # Use latest Truffle. Older versions crash on the output from 0.8.0.
     force_truffle_version ^5.1.55
 
-    run_install install_fn
+    run_install "$SOLJSON" install_fn
 
-    truffle_run_test compile_fn test_fn
+    truffle_run_test "$SOLJSON" compile_fn test_fn "NO-FORCE-ABI-V2"
 }
 
 external_test Ens ens_test
diff --git a/test/externalTests/gnosis.sh b/test/externalTests/gnosis.sh
index 8a5ccd0c7..73870f8db 100755
--- a/test/externalTests/gnosis.sh
+++ b/test/externalTests/gnosis.sh
@@ -33,17 +33,17 @@ function gnosis_safe_test
     OPTIMIZER_LEVEL=1
     CONFIG="truffle.js"
 
-    truffle_setup https://github.com/solidity-external-tests/safe-contracts.git development_070
+    truffle_setup "$SOLJSON" https://github.com/solidity-external-tests/safe-contracts.git development_070
 
     force_truffle_version ^5.0.42
     sed -i 's|github:gnosis/mock-contract#sol_0_5_0|github:solidity-external-tests/mock-contract#master_070|g' package.json
     rm -f package-lock.json
     rm -rf node_modules/
 
-    run_install install_fn
+    run_install "$SOLJSON" install_fn
     replace_libsolc_call
 
-    truffle_run_test compile_fn test_fn
+    truffle_run_test "$SOLJSON" compile_fn test_fn "NO-FORCE-ABI-V2"
 }
 
 external_test Gnosis-Safe gnosis_safe_test
diff --git a/test/externalTests/solc-js/solc-js.sh b/test/externalTests/solc-js/solc-js.sh
index db01a2ae7..9cc753959 100755
--- a/test/externalTests/solc-js/solc-js.sh
+++ b/test/externalTests/solc-js/solc-js.sh
@@ -35,16 +35,16 @@ function solcjs_test
     SOLCJS_INPUT_DIR="$TEST_DIR"/test/externalTests/solc-js
 
     # set up solc-js on the branch specified
-    setup master
+    setup "$SOLJSON" master
 
     printLog "Updating index.js file..."
     echo "require('./determinism.js');" >> test/index.js
 
     printLog "Copying determinism.js..."
-    cp -f $SOLCJS_INPUT_DIR/determinism.js test/
+    cp -f "$SOLCJS_INPUT_DIR/determinism.js" test/
 
     printLog "Copying contracts..."
-    cp -Rf $SOLCJS_INPUT_DIR/DAO test/
+    cp -Rf "$SOLCJS_INPUT_DIR/DAO" test/
 
     printLog "Copying SMTChecker tests..."
     cp -Rf "$TEST_DIR"/test/libsolidity/smtCheckerTests test/
@@ -52,7 +52,7 @@ function solcjs_test
 
     # Update version (needed for some tests)
     echo "Updating package.json to version $VERSION"
-    npm version --allow-same-version --no-git-tag-version $VERSION
+    npm version --allow-same-version --no-git-tag-version "$VERSION"
 
     run_test compile_fn test_fn
 }
diff --git a/test/externalTests/zeppelin.sh b/test/externalTests/zeppelin.sh
index 51051f334..e71e974d6 100755
--- a/test/externalTests/zeppelin.sh
+++ b/test/externalTests/zeppelin.sh
@@ -33,10 +33,10 @@ function zeppelin_test
     OPTIMIZER_LEVEL=1
     CONFIG="truffle-config.js"
 
-    truffle_setup https://github.com/solidity-external-tests/openzeppelin-contracts.git upgrade-0.7.0
-    run_install install_fn
+    truffle_setup "$SOLJSON" https://github.com/solidity-external-tests/openzeppelin-contracts.git upgrade-0.7.0
+    run_install "$SOLJSON" install_fn
 
-    truffle_run_test compile_fn test_fn
+    truffle_run_test "$SOLJSON" compile_fn test_fn "NO-FORCE-ABI-V2"
 }
 
 external_test Zeppelin zeppelin_test