diff --git a/spacy/schemas.py b/spacy/schemas.py
index d8bcf3c1d..2030048d8 100644
--- a/spacy/schemas.py
+++ b/spacy/schemas.py
@@ -198,7 +198,7 @@ class ModelMetaSchema(BaseModel):
 class ConfigSchemaTraining(BaseModel):
     # fmt: off
     vectors: Optional[StrictStr] = Field(..., title="Path to vectors")
-    corpus: Reader = Field(..., title="Reader for the training and dev data")
+    corpus: Dict[str, Reader] = Field(..., title="Reader for the training and dev data")
     batcher: Batcher = Field(..., title="Batcher for the training data")
     dropout: StrictFloat = Field(..., title="Dropout rate")
     patience: StrictInt = Field(..., title="How many steps to continue without improvement in evaluation score")