diff --git a/python/cuml/fil/fil.pyx b/python/cuml/fil/fil.pyx
index eb9b26a5cc..b8b6f72913 100644
--- a/python/cuml/fil/fil.pyx
+++ b/python/cuml/fil/fil.pyx
@@ -50,16 +50,19 @@ cimport cuml.common.cuda
 
 cdef extern from "treelite/c_api.h":
     ctypedef void* ModelHandle
-    cdef int TreeliteLoadXGBoostModel(const char* filename,
-                                      ModelHandle* out) except +
-    cdef int TreeliteLoadXGBoostJSON(const char* filename,
-                                     ModelHandle* out) except +
+    cdef int TreeliteLoadXGBoostModelEx(const char* filename,
+                                        const char* config_json,
+                                        ModelHandle* out) except +
+    cdef int TreeliteLoadXGBoostJSONEx(const char* filename,
+                                       const char* config_json,
+                                       ModelHandle* out) except +
     cdef int TreeliteFreeModel(ModelHandle handle) except +
     cdef int TreeliteQueryNumTree(ModelHandle handle, size_t* out) except +
     cdef int TreeliteQueryNumFeature(ModelHandle handle, size_t* out) except +
     cdef int TreeliteQueryNumClass(ModelHandle handle, size_t* out) except +
-    cdef int TreeliteLoadLightGBMModel(const char* filename,
-                                       ModelHandle* out) except +
+    cdef int TreeliteLoadLightGBMModelEx(const char* filename,
+                                         const char* config_json,
+                                         ModelHandle* out) except +
     cdef int TreeliteSerializeModel(const char* filename,
                                     ModelHandle handle) except +
     cdef int TreeliteDeserializeModel(const char* filename,
@@ -137,14 +140,15 @@ cdef class TreeliteModel():
             Type of model: 'xgboost', 'xgboost_json', or 'lightgbm'
         """
         filename_bytes = filename.encode("UTF-8")
+        config_bytes = "{}".encode("UTF-8")
         cdef ModelHandle handle
         if model_type == "xgboost":
-            res = TreeliteLoadXGBoostModel(filename_bytes, &handle)
+            res = TreeliteLoadXGBoostModelEx(filename_bytes, config_bytes, &handle)
             if res < 0:
                 err = TreeliteGetLastError()
                 raise RuntimeError("Failed to load %s (%s)" % (filename, err))
         elif model_type == "xgboost_json":
-            res = TreeliteLoadXGBoostJSON(filename_bytes, &handle)
+            res = TreeliteLoadXGBoostJSONEx(filename_bytes, config_bytes, &handle)
             if res < 0:
                 err = TreeliteGetLastError()
                 raise RuntimeError("Failed to load %s (%s)" % (filename, err))
@@ -152,7 +156,7 @@ cdef class TreeliteModel():
             logger.warn("Treelite currently does not support float64 model"
                         " parameters. Accuracy may degrade slightly relative"
                         " to native LightGBM invocation.")
-            res = TreeliteLoadLightGBMModel(filename_bytes, &handle)
+            res = TreeliteLoadLightGBMModelEx(filename_bytes, config_bytes, &handle)
             if res < 0:
                 err = TreeliteGetLastError()
                 raise RuntimeError("Failed to load %s (%s)" % (filename, err))