diff --git a/shared/threat-models/ext/supported-threat-models.model.json b/shared/threat-models/ext/supported-threat-models.model.json
new file mode 100644
index 000000000000..d4162bde1250
--- /dev/null
+++ b/shared/threat-models/ext/supported-threat-models.model.json
@@ -0,0 +1,13 @@
+{
+  "extensions": [
+    {
+      "addsTo": {
+        "pack": "codeql/threat-models",
+        "extensible": "threatModelConfiguration"
+      },
+      "data": [
+        ["default", true, -2147483648] // The "default" threat model is included by default
+      ]
+    }
+  ]
+}
diff --git a/shared/threat-models/ext/supported-threat-models.model.yml b/shared/threat-models/ext/supported-threat-models.model.yml
deleted file mode 100644
index 59589f50f386..000000000000
--- a/shared/threat-models/ext/supported-threat-models.model.yml
+++ /dev/null
@@ -1,6 +0,0 @@
-extensions:
-  - addsTo:
-      pack: codeql/threat-models
-      extensible: threatModelConfiguration
-    data:
-      - ["default", true, -2147483648] # The "default" threat model is included by default
diff --git a/shared/threat-models/ext/threat-model-grouping.model.json b/shared/threat-models/ext/threat-model-grouping.model.json
new file mode 100644
index 000000000000..cc33d4ed0d09
--- /dev/null
+++ b/shared/threat-models/ext/threat-model-grouping.model.json
@@ -0,0 +1,41 @@
+{
+  "extensions": [
+    {
+      "addsTo": {
+        "pack": "codeql/threat-models",
+        "extensible": "threatModelGrouping"
+      },
+      "data": [
+        // Default threat model
+        ["remote", "default"],
+
+        // Remote threat models
+        ["request", "remote"],
+        ["response", "remote"],
+
+        // Local threat models
+        ["database", "local"],
+        ["commandargs", "local"],
+        ["environment", "local"],
+        ["stdin", "local"],
+        ["file", "local"],
+        ["windows-registry", "local"],
+
+        // Android threat models
+        ["android-external-storage-dir", "android"],
+        ["contentprovider", "android"],
+
+        // Threat models that are not grouped with any other threat models.
+        // (Note that all threat models are a child of "all" implicitly, and we
+        // make it explicit here just to make sure all threat models are listed.)
+        ["database-access-result", "all"],
+        ["file-write", "all"],
+        ["reverse-dns", "all"],
+        ["view-component-input", "all"],
+
+        // AI threat models
+        ["ai", "all"]
+      ]
+    }
+  ]
+}
diff --git a/shared/threat-models/ext/threat-model-grouping.model.yml b/shared/threat-models/ext/threat-model-grouping.model.yml
deleted file mode 100644
index 414cbda6fabe..000000000000
--- a/shared/threat-models/ext/threat-model-grouping.model.yml
+++ /dev/null
@@ -1,34 +0,0 @@
-extensions:
-
-  - addsTo:
-      pack: codeql/threat-models
-      extensible: threatModelGrouping
-    data:
-      # Default threat model
-      - ["remote", "default"]
-
-      # Remote threat models
-      - ["request", "remote"]
-      - ["response", "remote"]
-
-      # Local threat models
-      - ["database", "local"]
-      - ["commandargs", "local"]
-      - ["environment", "local"]
-      - ["stdin", "local"]
-      - ["file", "local"]
-      - ["windows-registry", "local"]
-
-      # Android threat models
-      - ["android-external-storage-dir", "android"]
-      - ["contentprovider", "android"]
-
-      # Threat models that are not grouped with any other threat models.
-      # (Note that all threat models are a child of "all" implicitly, and we
-      # make it explicit here just to make sure all threat models are listed.)
-      - ["database-access-result", "all"]
-      - ["file-write", "all"]
-      - ["reverse-dns", "all"]
-      - ["view-component-input", "all"]
-      # AI threat models
-      - ["ai", "all"]
diff --git a/shared/threat-models/qlpack.yml b/shared/threat-models/qlpack.yml
index 23ea2cf9c981..c20e02c1f82f 100644
--- a/shared/threat-models/qlpack.yml
+++ b/shared/threat-models/qlpack.yml
@@ -4,4 +4,5 @@ library: true
 groups: shared
 dataExtensions:
   - ext/*.model.yml
+  - ext/*.model.json
 warnOnImplicitThis: true
diff --git a/shared/util/ext/default-alert-filter.json b/shared/util/ext/default-alert-filter.json
new file mode 100644
index 000000000000..a204b5a5a4df
--- /dev/null
+++ b/shared/util/ext/default-alert-filter.json
@@ -0,0 +1,20 @@
+{
+  "extensions": [
+    {
+      "addsTo": {
+        "pack": "codeql/util",
+        "extensible": "restrictAlertsTo"
+      },
+      // Empty predicate means no restrictions on alert locations
+      "data": []
+    },
+    {
+      "addsTo": {
+        "pack": "codeql/util",
+        "extensible": "restrictAlertsToExactLocation"
+      },
+      // Empty predicate means no restrictions on alert locations
+      "data": []
+    }
+  ]
+}
diff --git a/shared/util/ext/default-alert-filter.yml b/shared/util/ext/default-alert-filter.yml
deleted file mode 100644
index 1c4dd263d055..000000000000
--- a/shared/util/ext/default-alert-filter.yml
+++ /dev/null
@@ -1,13 +0,0 @@
-extensions:
-
-  - addsTo:
-      pack: codeql/util
-      extensible: restrictAlertsTo
-    # Empty predicate means no restrictions on alert locations
-    data: []
-
-  - addsTo:
-      pack: codeql/util
-      extensible: restrictAlertsToExactLocation
-    # Empty predicate means no restrictions on alert locations
-    data: []
diff --git a/shared/util/qlpack.yml b/shared/util/qlpack.yml
index 8e1207a4eea1..ccb1887d91cf 100644
--- a/shared/util/qlpack.yml
+++ b/shared/util/qlpack.yml
@@ -5,4 +5,5 @@ library: true
 dependencies: null
 dataExtensions:
   - ext/*.yml
+  - ext/*.json
 warnOnImplicitThis: true