diff --git a/.github/workflows/pre-commit.yaml b/.github/workflows/pre-commit.yaml
index 07241d1a0..6f2ec84ff 100644
--- a/.github/workflows/pre-commit.yaml
+++ b/.github/workflows/pre-commit.yaml
@@ -21,6 +21,10 @@ jobs:
       run: |
         curl -L "$(curl -s https://api.github.com/repos/mvdan/sh/releases/latest | grep -o -E -m 1 "https://.+?linux_amd64")" > shfmt \
         && chmod +x shfmt && sudo mv shfmt /usr/bin/
+
+    - name: Install shellcheck
+      run: |
+        sudo apt update && sudo apt install shellcheck
     # Need to success pre-commit fix push
     - uses: actions/checkout@v2
       with:
diff --git a/.pre-commit-config.yaml b/.pre-commit-config.yaml
index f1a7a65ef..f876ccd35 100644
--- a/.pre-commit-config.yaml
+++ b/.pre-commit-config.yaml
@@ -33,3 +33,4 @@ repos:
   hooks:
     - id: shfmt
       args: ['-l', '-i', '2', '-ci', '-sr', '-w']
+    - id: shellcheck
diff --git a/infracost_breakdown.sh b/infracost_breakdown.sh
index c56e4cd73..f2cb816dd 100755
--- a/infracost_breakdown.sh
+++ b/infracost_breakdown.sh
@@ -62,6 +62,7 @@ function common::parse_cmdline {
         ;;
       --)
         shift
+        # shellcheck disable=SC2034 # Common function
         FILES=("$@")
         break
         ;;
@@ -101,6 +102,7 @@ function infracost_breakdown_ {
     # $hook_config receives string like '1 > 2; 3 == 4;' etc.
     # It gets split by `;` into array, which we're parsing here ('1 > 2' ' 3 == 4')
     # Next line removes leading spaces, just for fancy output reason.
+    # shellcheck disable=SC2001 # Rule exception
     check=$(echo "$check" | sed 's/^[[:space:]]*//')
 
     # Drop quotes in hook args section. From:
@@ -116,7 +118,7 @@ function infracost_breakdown_ {
     }; then
       check="${check:1:-1}"
     fi
-
+    # shellcheck disable=SC2207 # Can't find working `read` command
     operations=($(echo "$check" | grep -oE '[!<>=]{1,2}'))
     # Get the very last operator, that is used in comparison inside `jq` query.
     # From the example below we need to pick the `>` which is in between `add` and `1000`,
diff --git a/terraform_docs.sh b/terraform_docs.sh
index 0c1e71159..f2efb0af7 100755
--- a/terraform_docs.sh
+++ b/terraform_docs.sh
@@ -121,9 +121,11 @@ function terraform_docs {
   local add_to_existing=false
   local create_if_not_exist=false
 
-  configs=($hook_config)
+  read -r -a configs <<< "$hook_config"
+
   for c in "${configs[@]}"; do
-    config=(${c//=/ })
+
+    IFS="=" read -r -a config <<< "$c"
     key=${config[0]}
     value=${config[1]}
 
@@ -161,9 +163,11 @@ function terraform_docs {
       dir="$(dirname "$text_file")"
 
       mkdir -p "$dir"
-      echo -e "# ${PWD##*/}\n" >> "$text_file"
-      echo "<!-- BEGINNING OF PRE-COMMIT-TERRAFORM DOCS HOOK -->" >> "$text_file"
-      echo "<!-- END OF PRE-COMMIT-TERRAFORM DOCS HOOK -->" >> "$text_file"
+      {
+        echo -e "# ${PWD##*/}\n"
+        echo "<!-- BEGINNING OF PRE-COMMIT-TERRAFORM DOCS HOOK -->"
+        echo "<!-- END OF PRE-COMMIT-TERRAFORM DOCS HOOK -->"
+      } >> "$text_file"
     fi
 
     # If file still not exist - skip dir
diff --git a/tests/hooks_performance_test.sh b/tests/hooks_performance_test.sh
index 342bb302e..4f35fce23 100755
--- a/tests/hooks_performance_test.sh
+++ b/tests/hooks_performance_test.sh
@@ -44,33 +44,33 @@ function generate_table {
 | time command   | max    | min    | mean     | median |
 | -------------- | ------ | ------ | -------- | ------ |
 | users seconds  | $(
-    printf %"s\n" $users_seconds | datamash max 1
+    printf %"s\n" "$users_seconds" | datamash max 1
   ) | $(
-    printf %"s\n" $users_seconds | datamash min 1
+    printf %"s\n" "$users_seconds" | datamash min 1
   ) | $(
-    printf %"s\n" $users_seconds | datamash mean 1
-  ) | $(printf %"s\n" $users_seconds | datamash median 1) |
+    printf %"s\n" "$users_seconds" | datamash mean 1
+  ) | $(printf %"s\n" "$users_seconds" | datamash median 1) |
 | system seconds | $(
-    printf %"s\n" $system_seconds | datamash max 1
+    printf %"s\n" "$system_seconds" | datamash max 1
   ) | $(
-    printf %"s\n" $system_seconds | datamash min 1
+    printf %"s\n" "$system_seconds" | datamash min 1
   ) | $(
-    printf %"s\n" $system_seconds | datamash mean 1
-  ) | $(printf %"s\n" $system_seconds | datamash median 1) |
+    printf %"s\n" "$system_seconds" | datamash mean 1
+  ) | $(printf %"s\n" "$system_seconds" | datamash median 1) |
 | CPU %          | $(
-    printf %"s\n" $cpu | datamash max 1
+    printf %"s\n" "$cpu" | datamash max 1
   ) | $(
-    printf %"s\n" $cpu | datamash min 1
+    printf %"s\n" "$cpu" | datamash min 1
   ) | $(
-    printf %"s\n" $cpu | datamash mean 1
-  ) | $(printf %"s\n" $cpu | datamash median 1) |
+    printf %"s\n" "$cpu" | datamash mean 1
+  ) | $(printf %"s\n" "$cpu" | datamash median 1) |
 | Total time     | $(
-    printf %"s\n" $total_time | datamash max 1
+    printf %"s\n" "$total_time" | datamash max 1
   ) | $(
-    printf %"s\n" $total_time | datamash min 1
+    printf %"s\n" "$total_time" | datamash min 1
   ) | $(
-    printf %"s\n" $total_time | datamash mean 1
-  ) | $(printf %"s\n" $total_time | datamash median 1) |
+    printf %"s\n" "$total_time" | datamash mean 1
+  ) | $(printf %"s\n" "$total_time" | datamash median 1) |
 "
 }
 
@@ -82,8 +82,7 @@ function save_result {
 
   local FILE_NAME=${5:-"tests_result.md"}
 
-  echo -e "\n$DESCRIPTION" >> "tests/results/$FILE_NAME"
-  echo -e "$TABLE" >> "tests/results/$FILE_NAME"
+  echo -e "\n$DESCRIPTION\n$TABLE" >> "tests/results/$FILE_NAME"
   # shellcheck disable=SC2016,SC2128 # Irrelevant
   echo -e '
 <details><summary>Run details</summary>