diff --git a/colbert/indexing/utils.py b/colbert/indexing/utils.py
index 92f0954b..b7f80507 100644
--- a/colbert/indexing/utils.py
+++ b/colbert/indexing/utils.py
@@ -44,6 +44,15 @@ def optimize_ivf(orig_ivf, orig_ivf_lengths, index_path, verbose:int=3):
         offset += length
     ivf = torch.cat(unique_pids_per_centroid)
     ivf_lengths = torch.tensor(ivf_lengths)
+    
+    max_stride = ivf_lengths.max().item()
+    zero = torch.zeros(1, dtype=torch.long, device=ivf_lengths.device)
+    offsets = torch.cat((zero, torch.cumsum(ivf_lengths, dim=0)))
+    inner_dims = ivf.size()[1:]
+
+    if offsets[-2] + max_stride > ivf.size(0):
+        padding = torch.zeros(max_stride, *inner_dims, dtype=ivf.dtype, device=ivf.device)
+        ivf = torch.cat((ivf, padding))
 
     original_ivf_path = os.path.join(index_path, 'ivf.pt')
     optimized_ivf_path = os.path.join(index_path, 'ivf.pid.pt')
diff --git a/colbert/search/decompress_residuals.cpp b/colbert/search/decompress_residuals.cpp
index fbca4f80..f6ef4451 100644
--- a/colbert/search/decompress_residuals.cpp
+++ b/colbert/search/decompress_residuals.cpp
@@ -156,5 +156,5 @@ torch::Tensor decompress_residuals(
 
 PYBIND11_MODULE(TORCH_EXTENSION_NAME, m) {
     m.def("decompress_residuals_cpp", &decompress_residuals,
-          "Decompress residuals");
+          "Decompress residuals", py::call_guard<py::gil_scoped_release>());
 }
diff --git a/colbert/search/filter_pids.cpp b/colbert/search/filter_pids.cpp
index a85e4425..57564c64 100644
--- a/colbert/search/filter_pids.cpp
+++ b/colbert/search/filter_pids.cpp
@@ -170,5 +170,5 @@ torch::Tensor filter_pids(const torch::Tensor pids,
 }
 
 PYBIND11_MODULE(TORCH_EXTENSION_NAME, m) {
-    m.def("filter_pids_cpp", &filter_pids, "Filter pids");
+    m.def("filter_pids_cpp", &filter_pids, "Filter pids", py::call_guard<py::gil_scoped_release>());
 }