diff --git a/.github/workflows/docker-build-push-ecr.yaml b/.github/workflows/docker-build-push-ecr.yaml
index ae2f17c4..53f623e5 100644
--- a/.github/workflows/docker-build-push-ecr.yaml
+++ b/.github/workflows/docker-build-push-ecr.yaml
@@ -69,7 +69,7 @@ jobs:
           ARTIFACT_PATH: ${{ inputs.artifact_path || vars.artifact_path }}
           ARTIFACT_NAME: ${{ inputs.artifact_name || vars.artifact_name }}
           ARTIFACT_PATTERN: ${{ inputs.artifact_pattern || vars.artifact_pattern }}
-          ARTIFACT_MERGE_MULTIPLE: ${{ inputs.artifact_merge_multiple || vars.artifact_merge_multiple }}
+          ARTIFACT_MERGE_MULTIPLE: ${{ inputs.artifact_merge_multiple || vars.artifact_merge_multiple || false}}
         uses: actions/download-artifact@fa0a91b85d4f404e444e00e005971372dc801d16 # v4
         if: env.ARTIFACT_PATH != '' || env.ARTIFACT_NAME != ''
         with:
diff --git a/.github/workflows/tf-apply.yaml b/.github/workflows/tf-apply.yaml
index 4d23db56..ab6b7322 100644
--- a/.github/workflows/tf-apply.yaml
+++ b/.github/workflows/tf-apply.yaml
@@ -95,7 +95,7 @@ jobs:
           GH_ARTIFACT_PATH: ${{ inputs.gh_artifact_path || vars.gh_artifact_path }}
           GH_ARTIFACT_NAME: ${{ inputs.gh_artifact_name || vars.gh_artifact_name }}
           GH_ARTIFACT_PATTERN: ${{ inputs.gh_artifact_pattern || vars.gh_artifact_pattern }}
-          GH_ARTIFACT_MERGE_MULTIPLE: ${{ inputs.gh_artifact_merge_multiple || vars.gh_artifact_merge_multiple }}
+          GH_ARTIFACT_MERGE_MULTIPLE: ${{ inputs.gh_artifact_merge_multiple || vars.gh_artifact_merge_multiple || false }}
         uses: actions/download-artifact@fa0a91b85d4f404e444e00e005971372dc801d16 # v4
         if: env.GH_ARTIFACT_PATH != '' || env.GH_ARTIFACT_NAME != ''
         with:
diff --git a/.github/workflows/tf-feature.yaml b/.github/workflows/tf-feature.yaml
index 40ce2eef..4823da70 100644
--- a/.github/workflows/tf-feature.yaml
+++ b/.github/workflows/tf-feature.yaml
@@ -101,7 +101,7 @@ jobs:
           GH_ARTIFACT_PATH: ${{ inputs.gh_artifact_path || vars.gh_artifact_path }}
           GH_ARTIFACT_NAME: ${{ inputs.gh_artifact_name || vars.gh_artifact_name }}
           GH_ARTIFACT_PATTERN: ${{ inputs.gh_artifact_pattern || vars.gh_artifact_pattern }}
-          GH_ARTIFACT_MERGE_MULTIPLE: ${{ inputs.gh_artifact_merge_multiple || vars.gh_artifact_merge_multiple }}
+          GH_ARTIFACT_MERGE_MULTIPLE: ${{ inputs.gh_artifact_merge_multiple || vars.gh_artifact_merge_multiple || false }}
         uses: actions/download-artifact@fa0a91b85d4f404e444e00e005971372dc801d16 # v4
         if: env.GH_ARTIFACT_PATH != '' || env.GH_ARTIFACT_NAME != ''
         with:
diff --git a/.github/workflows/tf-plan.yaml b/.github/workflows/tf-plan.yaml
index c683d521..a249e53f 100644
--- a/.github/workflows/tf-plan.yaml
+++ b/.github/workflows/tf-plan.yaml
@@ -95,7 +95,7 @@ jobs:
           GH_ARTIFACT_PATH: ${{ inputs.gh_artifact_path || vars.gh_artifact_path }}
           GH_ARTIFACT_NAME: ${{ inputs.gh_artifact_name || vars.gh_artifact_name }}
           GH_ARTIFACT_PATTERN: ${{ inputs.gh_artifact_pattern || vars.gh_artifact_pattern }}
-          GH_ARTIFACT_MERGE_MULTIPLE: ${{ inputs.gh_artifact_merge_multiple || vars.gh_artifact_merge_multiple }}
+          GH_ARTIFACT_MERGE_MULTIPLE: ${{ inputs.gh_artifact_merge_multiple || vars.gh_artifact_merge_multiple || false }}
         uses: actions/download-artifact@fa0a91b85d4f404e444e00e005971372dc801d16 # v4
         if: env.GH_ARTIFACT_PATH != '' || env.GH_ARTIFACT_NAME != ''
         with: