diff --git a/packages/core/content-type-builder/server/utils/__tests__/attributes.test.js b/packages/core/content-type-builder/server/utils/__tests__/attributes.test.js
deleted file mode 100644
index 66525d33ad..0000000000
--- a/packages/core/content-type-builder/server/utils/__tests__/attributes.test.js
+++ /dev/null
@@ -1,34 +0,0 @@
-'use strict';
-
-const { formatAttribute } = require('../attributes');
-
-describe('format attributes', () => {
-  it('replaces type customField with the underlying data type', () => {
-    const mockAttribute = {
-      type: 'customField',
-      customField: 'plugin::mycustomfields.color',
-    };
-
-    global.strapi = {
-      container: {
-        // mock container.get('custom-fields')
-        get: jest.fn(() => ({
-          // mock container.get('custom-fields').get(uid)
-          get: jest.fn(() => ({
-            name: 'color',
-            plugin: 'mycustomfields',
-            type: 'text',
-          })),
-        })),
-      },
-    };
-
-    const formattedAttribute = formatAttribute('key', mockAttribute);
-
-    const expected = {
-      type: 'text',
-      customField: 'plugin::mycustomfields.color',
-    };
-    expect(formattedAttribute).toEqual(expected);
-  });
-});
diff --git a/packages/core/content-type-builder/server/utils/attributes.js b/packages/core/content-type-builder/server/utils/attributes.js
index 620a537811..e90fc1fd1a 100644
--- a/packages/core/content-type-builder/server/utils/attributes.js
+++ b/packages/core/content-type-builder/server/utils/attributes.js
@@ -67,15 +67,6 @@ const formatAttribute = (key, attribute) => {
     };
   }
 
-  if (attribute.type === 'customField') {
-    const customField = strapi.container.get('custom-fields').get(attribute.customField);
-
-    return {
-      ...attribute,
-      type: customField.type,
-    };
-  }
-
   return attribute;
 };
 
diff --git a/packages/core/strapi/lib/Strapi.js b/packages/core/strapi/lib/Strapi.js
index 91ad819181..19059fe207 100644
--- a/packages/core/strapi/lib/Strapi.js
+++ b/packages/core/strapi/lib/Strapi.js
@@ -40,6 +40,7 @@ const bootstrap = require('./core/bootstrap');
 const loaders = require('./core/loaders');
 const { destroyOnSignal } = require('./utils/signals');
 const sanitizersRegistry = require('./core/registries/sanitizers');
+const convertCustomFieldType = require('./utils/convert-custom-field-type');
 
 // TODO: move somewhere else
 const draftAndPublishSync = require('./migrations/draft-publish');
@@ -428,6 +429,8 @@ class Strapi {
 
   async load() {
     await this.register();
+    // Swap type customField for underlying data type
+    convertCustomFieldType(this);
     await this.bootstrap();
 
     this.isLoaded = true;
diff --git a/packages/core/strapi/lib/utils/__tests__/convert-custom-field-type.test.js b/packages/core/strapi/lib/utils/__tests__/convert-custom-field-type.test.js
new file mode 100644
index 0000000000..b4d255ef23
--- /dev/null
+++ b/packages/core/strapi/lib/utils/__tests__/convert-custom-field-type.test.js
@@ -0,0 +1,49 @@
+'use strict';
+
+const convertCustomFieldType = require('../convert-custom-field-type');
+
+describe('format attributes', () => {
+  it('replaces type customField with the underlying data type', () => {
+    global.strapi = {
+      container: {
+        // mock container.get('custom-fields')
+        get: jest.fn(() => ({
+          // mock container.get('custom-fields').get(uid)
+          get: jest.fn(() => ({
+            name: 'color',
+            plugin: 'mycustomfields',
+            type: 'text',
+          })),
+        })),
+      },
+      contentTypes: {
+        test: {
+          attributes: {
+            color: {
+              type: 'customField',
+              customField: 'plugin::mycustomfields.color',
+            },
+          },
+        },
+      },
+    };
+
+    convertCustomFieldType(global.strapi);
+
+    const expected = {
+      ...global.strapi,
+      contentTypes: {
+        test: {
+          attributes: {
+            color: {
+              type: 'text',
+              customField: 'plugin::mycustomfields.color',
+            },
+          },
+        },
+      },
+    };
+
+    expect(global.strapi).toEqual(expected);
+  });
+});
diff --git a/packages/core/strapi/lib/utils/convert-custom-field-type.js b/packages/core/strapi/lib/utils/convert-custom-field-type.js
new file mode 100644
index 0000000000..ba41f74af2
--- /dev/null
+++ b/packages/core/strapi/lib/utils/convert-custom-field-type.js
@@ -0,0 +1,15 @@
+'use strict';
+
+const convertCustomFieldType = strapi => {
+  const allSchemasAttributes = Object.values(strapi.contentTypes).map(schema => schema.attributes);
+  for (const schemaAttrbutes of allSchemasAttributes) {
+    for (const attribute of Object.values(schemaAttrbutes)) {
+      if (attribute.type === 'customField') {
+        const customField = strapi.container.get('custom-fields').get(attribute.customField);
+        attribute.type = customField.type;
+      }
+    }
+  }
+};
+
+module.exports = convertCustomFieldType;
diff --git a/packages/plugins/documentation/server/services/helpers/utils/clean-schema-attributes.js b/packages/plugins/documentation/server/services/helpers/utils/clean-schema-attributes.js
index b3fdc73925..0c8bc4a467 100644
--- a/packages/plugins/documentation/server/services/helpers/utils/clean-schema-attributes.js
+++ b/packages/plugins/documentation/server/services/helpers/utils/clean-schema-attributes.js
@@ -19,11 +19,6 @@ const cleanSchemaAttributes = (attributes, { typeMap = new Map(), isRequest = fa
       delete attributesCopy[prop].default;
     }
 
-    if (attribute.type === 'customField') {
-      const customField = strapi.container.get('custom-fields').get(attribute.customField);
-      attribute.type = customField.type;
-    }
-
     switch (attribute.type) {
       case 'password': {
         if (!isRequest) {