diff --git a/requirements.txt b/requirements.txt
index 0da0742..efab339 100644
--- a/requirements.txt
+++ b/requirements.txt
@@ -7,7 +7,7 @@ pyscf>=2.14.0
 # HPC / parallel
 mpi4py>=3.1
 numpy>=1.24
-scipy>=1.10
+scipy>=1.18.0
 
 # Optional: GPU acceleration (requires CUDA 12.2)
 # cupy-cuda12x>=12.0