diff --git a/hc/api/migrations/0061_webhook_values.py b/hc/api/migrations/0061_webhook_values.py
new file mode 100644
index 00000000..c7134b8d
--- /dev/null
+++ b/hc/api/migrations/0061_webhook_values.py
@@ -0,0 +1,60 @@
+# Generated by Django 2.2.1 on 2019-05-29 20:37
+
+import json
+
+from django.db import migrations
+
+
+def normalize_webhook_values(apps, schema_editor):
+    Channel = apps.get_model("api", "Channel")
+    for ch in Channel.objects.filter(kind="webhook").only("value"):
+        # The old format of url_down, url_up, post_data separated by newlines:
+        if not ch.value.startswith("{"):
+            parts = ch.value.split("\n")
+            url_down = parts[0]
+            url_up = parts[1] if len(parts) > 1 else ""
+            post_data = parts[2] if len(parts) > 2 else ""
+
+            ch.value = json.dumps(
+                {
+                    "method_down": "POST" if post_data else "GET",
+                    "url_down": url_down,
+                    "body_down": post_data,
+                    "headers_down": {},
+                    "method_up": "POST" if post_data else "GET",
+                    "url_up": url_up,
+                    "body_up": post_data,
+                    "headers_up": {},
+                }
+            )
+
+            ch.save()
+            continue
+
+        doc = json.loads(ch.value)
+        # Legacy "post_data" in doc -- use the legacy fields
+        if "post_data" in doc:
+            ch.value = json.dumps(
+                {
+                    "method_down": "POST" if doc["post_data"] else "GET",
+                    "url_down": doc["url_down"],
+                    "body_down": doc["post_data"],
+                    "headers_down": doc["headers"],
+                    "method_up": "POST" if doc["post_data"] else "GET",
+                    "url_up": doc["url_up"],
+                    "body_up": doc["post_data"],
+                    "headers_up": doc["headers"],
+                }
+            )
+
+            ch.save()
+            continue
+
+
+class Migration(migrations.Migration):
+
+    dependencies = [("api", "0060_tokenbucket")]
+
+    operations = [
+        migrations.RunPython(normalize_webhook_values, migrations.RunPython.noop)
+    ]