diff --git a/bin/app-json.py b/bin/app-json.py
index 9b83c0e7..6ff8cdc3 100755
--- a/bin/app-json.py
+++ b/bin/app-json.py
@@ -95,12 +95,12 @@ def get_app_versions(app_path):
 
     chdir(app_path)
 
-    tags = check_output(f"git tag --list", shell=True).strip()
+    tags = check_output(f"git tag --list", shell=True).decode("utf-8").strip().split()
 
     for tag in tags:
-        run(f"git checkout", shell=True)
+        run(f"git checkout {tag}", shell=True)
 
-        services_command = "yq e .services | keys | .[] compose*.yml"
+        services_command = "yq e '.services | keys | .[]' compose*.yml"
         services = check_output(services_command, shell=True).decode("utf-8").split()
 
         for service in services:
@@ -111,7 +111,7 @@ def get_app_versions(app_path):
                 if image in ("null", "---"):
                     continue
 
-                digest_command = f"skopeo inspect {image} | yq '.Digest'"
+                digest_command = f"skopeo inspect docker://{image} | jq '.Digest'"
                 output = check_output(digest_command, shell=True).decode("utf-8")
                 digest = output.strip().split(":")[-1][:8]
                 versions.append(