diff --git a/modules/lambda-image-build/main.tf b/modules/lambda-image-build/main.tf
index 33e32ef..38a4519 100644
--- a/modules/lambda-image-build/main.tf
+++ b/modules/lambda-image-build/main.tf
@@ -106,7 +106,7 @@ resource "null_resource" "build_and_push" {
   }
 
   provisioner "local-exec" {
-    interpreter = ["/bin/sh", "-c"]
+    interpreter = ["/bin/bash", "-c"]
     command     = <<-EOC
       set -euo pipefail
       # Use an ephemeral Docker config to avoid host keychain credential helper conflicts.
diff --git a/modules/lambda-image-public/main.tf b/modules/lambda-image-public/main.tf
index 332afad..177a59d 100644
--- a/modules/lambda-image-public/main.tf
+++ b/modules/lambda-image-public/main.tf
@@ -46,7 +46,7 @@ resource "null_resource" "build_and_push" {
   }
 
   provisioner "local-exec" {
-    interpreter = ["/bin/sh", "-c"]
+    interpreter = ["/bin/bash", "-c"]
     command     = <<-EOC
       set -euo pipefail
       # Use an ephemeral Docker config to avoid host keychain credential helper conflicts.
diff --git a/modules/lambda-image-republish/main.tf b/modules/lambda-image-republish/main.tf
index 78d423c..afa0b32 100644
--- a/modules/lambda-image-republish/main.tf
+++ b/modules/lambda-image-republish/main.tf
@@ -91,7 +91,7 @@ resource "null_resource" "republish_image" {
   }
 
   provisioner "local-exec" {
-    interpreter = ["/bin/sh", "-c"]
+    interpreter = ["/bin/bash", "-c"]
     command     = <<-EOC
       set -euo pipefail
       # Use an ephemeral Docker config to avoid host keychain credential helper conflicts.