diff --git a/lib/src/command/outdated.dart b/lib/src/command/outdated.dart
index c5978d6..eaabc34 100644
--- a/lib/src/command/outdated.dart
+++ b/lib/src/command/outdated.dart
@@ -434,10 +434,10 @@
   Map<String, Object> toJson() {
     return {
       'package': name,
-      'current': current?.version?.toString(),
-      'upgradable': upgradable?.version?.toString(),
-      'resolvable': resolvable?.version?.toString(),
-      'latest': latest?.version?.toString(),
+      'current': {'version': current?.version?.toString()},
+      'upgradable': {'version': upgradable?.version?.toString()},
+      'resolvable': {'version': resolvable?.version?.toString()},
+      'latest': {'version': latest?.version?.toString()},
     };
   }
 }
diff --git a/test/outdated/goldens/circular_dependencies.txt b/test/outdated/goldens/circular_dependencies.txt
index 582817b..d8141b0 100644
--- a/test/outdated/goldens/circular_dependencies.txt
+++ b/test/outdated/goldens/circular_dependencies.txt
@@ -4,10 +4,18 @@
   "packages": [
     {
       "package": "foo",
-      "current": "1.2.3",
-      "upgradable": "1.3.0",
-      "resolvable": "1.3.0",
-      "latest": "1.3.0"
+      "current": {
+        "version": "1.2.3"
+      },
+      "upgradable": {
+        "version": "1.3.0"
+      },
+      "resolvable": {
+        "version": "1.3.0"
+      },
+      "latest": {
+        "version": "1.3.0"
+      }
     }
   ]
 }
diff --git a/test/outdated/goldens/mutually_incompatible.txt b/test/outdated/goldens/mutually_incompatible.txt
index 9bee742..5bc3119 100644
--- a/test/outdated/goldens/mutually_incompatible.txt
+++ b/test/outdated/goldens/mutually_incompatible.txt
@@ -4,17 +4,33 @@
   "packages": [
     {
       "package": "bar",
-      "current": "1.0.0",
-      "upgradable": "1.0.0",
-      "resolvable": "1.0.0",
-      "latest": "2.0.0"
+      "current": {
+        "version": "1.0.0"
+      },
+      "upgradable": {
+        "version": "1.0.0"
+      },
+      "resolvable": {
+        "version": "1.0.0"
+      },
+      "latest": {
+        "version": "2.0.0"
+      }
     },
     {
       "package": "foo",
-      "current": "1.0.0",
-      "upgradable": "1.0.0",
-      "resolvable": "1.0.0",
-      "latest": "2.0.0"
+      "current": {
+        "version": "1.0.0"
+      },
+      "upgradable": {
+        "version": "1.0.0"
+      },
+      "resolvable": {
+        "version": "1.0.0"
+      },
+      "latest": {
+        "version": "2.0.0"
+      }
     }
   ]
 }
diff --git a/test/outdated/goldens/newer_versions.txt b/test/outdated/goldens/newer_versions.txt
index bdd3548..6a8b31d 100644
--- a/test/outdated/goldens/newer_versions.txt
+++ b/test/outdated/goldens/newer_versions.txt
@@ -4,38 +4,78 @@
   "packages": [
     {
       "package": "foo",
-      "current": "1.2.3",
-      "upgradable": "1.3.0",
-      "resolvable": "2.0.0",
-      "latest": "3.0.0"
+      "current": {
+        "version": "1.2.3"
+      },
+      "upgradable": {
+        "version": "1.3.0"
+      },
+      "resolvable": {
+        "version": "2.0.0"
+      },
+      "latest": {
+        "version": "3.0.0"
+      }
     },
     {
       "package": "builder",
-      "current": "1.2.3",
-      "upgradable": "1.3.0",
-      "resolvable": "2.0.0",
-      "latest": "2.0.0"
+      "current": {
+        "version": "1.2.3"
+      },
+      "upgradable": {
+        "version": "1.3.0"
+      },
+      "resolvable": {
+        "version": "2.0.0"
+      },
+      "latest": {
+        "version": "2.0.0"
+      }
     },
     {
       "package": "transitive",
-      "current": "1.2.3",
-      "upgradable": "1.3.0",
-      "resolvable": "1.3.0",
-      "latest": "2.0.0"
+      "current": {
+        "version": "1.2.3"
+      },
+      "upgradable": {
+        "version": "1.3.0"
+      },
+      "resolvable": {
+        "version": "1.3.0"
+      },
+      "latest": {
+        "version": "2.0.0"
+      }
     },
     {
       "package": "transitive2",
-      "current": null,
-      "upgradable": null,
-      "resolvable": "1.0.0",
-      "latest": "1.0.0"
+      "current": {
+        "version": null
+      },
+      "upgradable": {
+        "version": null
+      },
+      "resolvable": {
+        "version": "1.0.0"
+      },
+      "latest": {
+        "version": "1.0.0"
+      }
     },
     {
       "package": "transitive3",
-      "current": null,
-      "upgradable": null,
-      "resolvable": "1.0.0",
-      "latest": "1.0.0"
+      "current": {
+        "version": null
+      },
+      "upgradable": {
+        "version": null
+      },
+      "resolvable": {
+        "version": "1.0.0"
+      },
+      "latest": {
+        "version": "1.0.0"
+      }
     }
   ]
 }