diff --git a/podman-build-publish/action.yaml b/podman-build-publish/action.yaml
index 1e0b709..e6f81f4 100644
--- a/podman-build-publish/action.yaml
+++ b/podman-build-publish/action.yaml
@@ -12,10 +12,10 @@ inputs:
     required: true
   registry-username:
     description: Registry username for login.
-    required: true
+    required: false
   registry-password:
     description: Registry password for login.
-    required: true
+    required: false
   context:
     description: Build context path.
     required: false
@@ -61,6 +61,11 @@ runs:
       run: |
         set -euo pipefail
 
+        if [[ -z "${{ inputs.registry-username }}" || -z "${{ inputs.registry-password }}" ]]; then
+          echo "ERROR: registry-username and registry-password are required when push is enabled" >&2
+          exit 1
+        fi
+
         podman_args=(
           --root "${RUNNER_TEMP}/podman-root"
           --runroot "${RUNNER_TEMP}/podman-runroot"