diff --git a/script/install.d/25-terraform.sh b/script/install.d/25-terraform.sh
index a13caeb..b3771bc 100644
--- a/script/install.d/25-terraform.sh
+++ b/script/install.d/25-terraform.sh
@@ -7,11 +7,10 @@
 
 if ! command -v "terraform" &>/dev/null; then
     if [[ "$OSTYPE" == "linux-gnu"* ]]; then
-        # https://developer.hashicorp.com/terraform/tutorials/aws-get-started/install-cli#install-terraform
-        wget -O- https://apt.releases.hashicorp.com/gpg |
-            gpg --dearmor |
-            sudo tee /usr/share/keyrings/hashicorp-archive-keyring.gpg >/dev/null
-
+        terraform_keyring_path="/usr/share/keyrings/hashicorp-archive-keyring.gpg"
+        if [[ ! -f "$terraform_keyring_path" ]]; then
+            curl -fsSL https://apt.releases.hashicorp.com/gpg | sudo gpg --dearmor -o "$terraform_keyring_path"
+        fi
         echo "deb [signed-by=/usr/share/keyrings/hashicorp-archive-keyring.gpg] \
             https://apt.releases.hashicorp.com $(lsb_release -cs) main" |
             sudo tee /etc/apt/sources.list.d/hashicorp.list
diff --git a/script/install.d/50-redis.sh b/script/install.d/50-redis.sh
index fda8772..b2e44e0 100644
--- a/script/install.d/50-redis.sh
+++ b/script/install.d/50-redis.sh
@@ -7,7 +7,10 @@
 
 if ! command -v redis-client &>/dev/null; then
     if [[ "$OSTYPE" == "linux-gnu"* ]]; then
-        curl -fsSL https://packages.redis.io/gpg | sudo gpg --dearmor -o /usr/share/keyrings/redis-archive-keyring.gpg
+        redis_keyring_path="/usr/share/keyrings/redis-archive-keyring.gpg"
+        if [[ ! -f "$redis_keyring_path" ]]; then
+            curl -fsSL https://packages.redis.io/gpg | sudo gpg --dearmor -o "$redis_keyring_path"
+        fi
         echo "deb [signed-by=/usr/share/keyrings/redis-archive-keyring.gpg] https://packages.redis.io/deb $(lsb_release -cs) main" | sudo tee /etc/apt/sources.list.d/redis.list
         sudo apt-get install -qq redis
     elif [[ "$OSTYPE" == "darwin"* ]]; then