diff --git a/Cargo.lock b/Cargo.lock
index 6c96df8..c0818c3 100644
--- a/Cargo.lock
+++ b/Cargo.lock
@@ -2271,9 +2271,9 @@ dependencies = [
 
 [[package]]
 name = "redb"
-version = "2.6.3"
+version = "4.1.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "8eca1e9d98d5a7e9002d0013e18d5a9b000aee942eb134883a82f06ebffb6c01"
+checksum = "8e925444704b5f17d32bf42f5b6e2df050bceebc3dcd6e71cc73dafe8092e839"
 dependencies = [
  "libc",
 ]
diff --git a/Cargo.toml b/Cargo.toml
index d3a5f0a..a6295cf 100644
--- a/Cargo.toml
+++ b/Cargo.toml
@@ -89,7 +89,7 @@ tree-sitter-fortran = "0.6"
 petgraph = "0.8"
 # Pure-Rust embedded ACID KV (mmap, copy-on-write B-tree, MVCC snapshot reads).
 # Backs the per-repo on-disk shard store; no C/C++ toolchain, clean on Windows.
-redb = "2"
+redb = "4"
 # msgpack codec for shard node/edge/index values. Already used by the AST cache
 # (synaptic-extract `cache-binary`); reused here so we add no new codec.
 rmp-serde = "1"