diff --git a/internal/namespaces/instance/v1/custom_image.go b/internal/namespaces/instance/v1/custom_image.go
index 0164ce19af..6e9326be8b 100644
--- a/internal/namespaces/instance/v1/custom_image.go
+++ b/internal/namespaces/instance/v1/custom_image.go
@@ -152,23 +152,23 @@ func imageCreateBuilder(c *core.Command) *core.Command {
 
 // customImage is based on instance.Image, with additional information about the server
 type imageListItem struct {
-	ID                string
-	Name              string
-	Arch              instance.Arch
-	CreationDate      *time.Time
-	ModificationDate  *time.Time
-	DefaultBootscript *instance.Bootscript
-	ExtraVolumes      map[string]*instance.Volume
-	OrganizationID    string
-	ProjectID         string
-	Public            bool
-	RootVolume        *instance.VolumeSummary
-	State             instance.ImageState
+	ID                string                      `json:"id"`
+	Name              string                      `json:"name"`
+	Arch              instance.Arch               `json:"arch"`
+	CreationDate      *time.Time                  `json:"creation_date"`
+	ModificationDate  *time.Time                  `json:"modification_date"`
+	DefaultBootscript *instance.Bootscript        `json:"default_bootscript"`
+	ExtraVolumes      map[string]*instance.Volume `json:"extra_volumes"`
+	OrganizationID    string                      `json:"organization"`
+	ProjectID         string                      `json:"project"`
+	Public            bool                        `json:"public"`
+	RootVolume        *instance.VolumeSummary     `json:"root_volume"`
+	State             instance.ImageState         `json:"state"`
 
 	// Replace Image.FromServer
-	ServerID   string
-	ServerName string
-	Zone       scw.Zone
+	ServerID   string   `json:"server_id"`
+	ServerName string   `json:"server_name"`
+	Zone       scw.Zone `json:"zone"`
 }
 
 // imageListBuilder list the images for a given organization/project.
diff --git a/internal/namespaces/instance/v1/testdata/test-image-list-simple.golden b/internal/namespaces/instance/v1/testdata/test-image-list-simple.golden
index b4d6a45c46..823cb55b91 100644
--- a/internal/namespaces/instance/v1/testdata/test-image-list-simple.golden
+++ b/internal/namespaces/instance/v1/testdata/test-image-list-simple.golden
@@ -5,25 +5,25 @@ ID                                    NAME                      STATE      PUBLI
 🟩🟩🟩 JSON STDOUT 🟩🟩🟩
 [
   {
-    "ID": "1a5178fe-f813-404a-a31c-df3822256c43",
-    "Name": "cli-img-practical-banzai",
-    "Arch": "x86_64",
-    "CreationDate": "1970-01-01T00:00:00.0Z",
-    "ModificationDate": "1970-01-01T00:00:00.0Z",
-    "DefaultBootscript": null,
-    "ExtraVolumes": {},
-    "OrganizationID": "b8fdefc6-c926-4a47-af24-24f14f724d6a",
-    "ProjectID": "b8fdefc6-c926-4a47-af24-24f14f724d6a",
-    "Public": false,
-    "RootVolume": {
+    "id": "1a5178fe-f813-404a-a31c-df3822256c43",
+    "name": "cli-img-practical-banzai",
+    "arch": "x86_64",
+    "creation_date": "1970-01-01T00:00:00.0Z",
+    "modification_date": "1970-01-01T00:00:00.0Z",
+    "default_bootscript": null,
+    "extra_volumes": {},
+    "organization": "b8fdefc6-c926-4a47-af24-24f14f724d6a",
+    "project": "b8fdefc6-c926-4a47-af24-24f14f724d6a",
+    "public": false,
+    "root_volume": {
       "id": "032d525e-d014-4b48-aaed-ea7d2c611a94",
       "name": "cli-snp-gifted-solomon",
       "size": 20000000000,
       "volume_type": "l_ssd"
     },
-    "State": "available",
-    "ServerID": "",
-    "ServerName": "",
-    "Zone": "fr-par-1"
+    "state": "available",
+    "server_id": "",
+    "server_name": "",
+    "zone": "fr-par-1"
   }
 ]