diff --git a/charts/duckling/README.md b/charts/duckling/README.md
index d483051..c5773a1 100644
--- a/charts/duckling/README.md
+++ b/charts/duckling/README.md
@@ -42,7 +42,7 @@ Duckling is a Haskell library that parses text into structured data.
 | image.name | string | `"duckling"` | Duckling image name to use (relative to `registry`) |
 | image.pullPolicy | string | `"IfNotPresent"` | Duckling image pullPolicy |
 | image.pullSecrets | list | `[]` | Duckling repository pullSecret |
-| image.repository | string | `nil` | Override default registry + image.name for Duckling |
+| image.repository | string | `""` | Override default registry + image.name for Duckling |
 | image.tag | string | `"0.1.6.5-r3"` | Duckling image tag to use |
 | ingress.annotations | object | `{}` | Ingress annotations |
 | ingress.enabled | bool | `false` | Set to true to enable ingress |
diff --git a/charts/duckling/values.schema.json b/charts/duckling/values.schema.json
index cea09be..2a9dda9 100644
--- a/charts/duckling/values.schema.json
+++ b/charts/duckling/values.schema.json
@@ -64,7 +64,7 @@
                     "type": "array"
                 },
                 "repository": {
-                    "type": "null"
+                    "type": "string"
                 },
                 "tag": {
                     "type": "string"
diff --git a/charts/duckling/values.yaml b/charts/duckling/values.yaml
index e989651..656cabe 100644
--- a/charts/duckling/values.yaml
+++ b/charts/duckling/values.yaml
@@ -41,7 +41,7 @@ image:
   tag: "0.1.6.5-r3"
 
   # -- Override default registry + image.name for Duckling
-  repository:
+  repository: ""
 
   # -- Duckling image pullPolicy
   pullPolicy: IfNotPresent
diff --git a/charts/rasa-action-server/README.md b/charts/rasa-action-server/README.md
index d5739e5..a667b3f 100644
--- a/charts/rasa-action-server/README.md
+++ b/charts/rasa-action-server/README.md
@@ -40,7 +40,7 @@ Rasa Action Server Helm chart for Kubernetes
 | image.name | string | `"rasa-x-demo"` | Action Server image name to use (relative to `registry`) |
 | image.pullPolicy | string | `"IfNotPresent"` | Action Server image pullPolicy |
 | image.pullSecrets | list | `[]` | Action Server repository pullSecret |
-| image.repository | string | `nil` | Override default registry + image.name for Action Server |
+| image.repository | string | `""` | Override default registry + image.name for Action Server |
 | image.tag | string | `"0.40.0"` | Action Server image tag to use |
 | ingress.annotations | object | `{}` | Ingress annotations |
 | ingress.enabled | bool | `false` | Set to true to enable ingress |
diff --git a/charts/rasa-action-server/values.schema.json b/charts/rasa-action-server/values.schema.json
index cea09be..2a9dda9 100644
--- a/charts/rasa-action-server/values.schema.json
+++ b/charts/rasa-action-server/values.schema.json
@@ -64,7 +64,7 @@
                     "type": "array"
                 },
                 "repository": {
-                    "type": "null"
+                    "type": "string"
                 },
                 "tag": {
                     "type": "string"
diff --git a/charts/rasa-action-server/values.yaml b/charts/rasa-action-server/values.yaml
index 380b0d3..738144d 100644
--- a/charts/rasa-action-server/values.yaml
+++ b/charts/rasa-action-server/values.yaml
@@ -41,7 +41,7 @@ image:
   tag: "0.40.0"
 
   # -- Override default registry + image.name for Action Server
-  repository:
+  repository: ""
 
   # -- Action Server image pullPolicy
   pullPolicy: IfNotPresent
diff --git a/charts/rasa/README.md b/charts/rasa/README.md
index a6da977..440df24 100644
--- a/charts/rasa/README.md
+++ b/charts/rasa/README.md
@@ -306,7 +306,7 @@ In the [`examples/rasa`](../../examples) directory you can find more detailed ex
 | image.name | string | `"rasa"` | Rasa Open Source image name to use (relative to `registry`) |
 | image.pullPolicy | string | `"IfNotPresent"` | Rasa Open Source image pullPolicy |
 | image.pullSecrets | list | `[]` | Rasa Open Source repository pullSecret |
-| image.repository | string | `nil` | Override default registry + image.name for Rasa Open Source |
+| image.repository | string | `""` | Override default registry + image.name for Rasa Open Source |
 | image.tag | string | `"2.7.1"` | Rasa Open Source image tag to use |
 | ingress.annotations | object | `{}` | Ingress annotations |
 | ingress.enabled | bool | `false` | Set to true to enable ingress |
diff --git a/charts/rasa/values.schema.json b/charts/rasa/values.schema.json
index 75d96a0..4687e4a 100644
--- a/charts/rasa/values.schema.json
+++ b/charts/rasa/values.schema.json
@@ -304,7 +304,7 @@
                     "type": "array"
                 },
                 "repository": {
-                    "type": "null"
+                    "type": "string"
                 },
                 "tag": {
                     "type": "string"
diff --git a/charts/rasa/values.yaml b/charts/rasa/values.yaml
index b5e766c..2ff04ee 100644
--- a/charts/rasa/values.yaml
+++ b/charts/rasa/values.yaml
@@ -219,7 +219,7 @@ image:
   tag: "2.7.1"
 
   # -- Override default registry + image.name for Rasa Open Source
-  repository:
+  repository: ""
 
   # -- Rasa Open Source image pullPolicy
   pullPolicy: IfNotPresent