diff --git a/schema/campaign_spec.schema.json b/schema/campaign_spec.schema.json
index d1d33ae8adf3..deacad369c52 100644
--- a/schema/campaign_spec.schema.json
+++ b/schema/campaign_spec.schema.json
@@ -81,6 +81,13 @@
             "additionalProperties": {
               "type": "string"
             }
+          },
+          "files": {
+            "type": "object",
+            "description": "Files that should be mounted into or be created inside the Docker container.",
+            "additionalProperties": {
+              "type": "string"
+            }
           }
         }
       }
diff --git a/schema/campaign_spec_stringdata.go b/schema/campaign_spec_stringdata.go
index 39e563d2f414..df497571ea6f 100644
--- a/schema/campaign_spec_stringdata.go
+++ b/schema/campaign_spec_stringdata.go
@@ -86,6 +86,13 @@ const CampaignSpecSchemaJSON = `{
             "additionalProperties": {
               "type": "string"
             }
+          },
+          "files": {
+            "type": "object",
+            "description": "Files that should be mounted into or be created inside the Docker container.",
+            "additionalProperties": {
+              "type": "string"
+            }
           }
         }
       }
diff --git a/schema/schema.go b/schema/schema.go
index 4faca8c05468..8b0f8da63563 100644
--- a/schema/schema.go
+++ b/schema/schema.go
@@ -1249,6 +1249,8 @@ type Step struct {
 	Container string `json:"container"`
 	// Env description: Environment variables to set in the environment when running this command.
 	Env map[string]string `json:"env,omitempty"`
+	// Files description: Files that should be mounted into or be created inside the Docker container.
+	Files map[string]string `json:"files,omitempty"`
 	// Run description: The shell command to run in the container. It can also be a multi-line shell script. The working directory is the root directory of the repository checkout.
 	Run string `json:"run"`
 }