diff --git a/fastembed/sparse/splade_pp.py b/fastembed/sparse/splade_pp.py
index 1183f214..2b05b653 100644
--- a/fastembed/sparse/splade_pp.py
+++ b/fastembed/sparse/splade_pp.py
@@ -41,7 +41,7 @@ def _post_process_onnx_output(
         if output.attention_mask is None:
             raise ValueError("attention_mask must be provided for document post-processing")
 
-        relu_log = np.log(1 + np.maximum(output.model_output, 0))
+        relu_log = np.log1p(np.maximum(output.model_output, 0))
 
         weighted_log = relu_log * np.expand_dims(output.attention_mask, axis=-1)