diff --git a/contrib/lockfile.sh b/contrib/lockfile.sh
index 39f68d53f..eae3fa10f 100644
--- a/contrib/lockfile.sh
+++ b/contrib/lockfile.sh
@@ -16,6 +16,10 @@ _cleanup_lockfile() {
 
 use_lockfile() {
     local src="$1"
+    # Already in place, from an enclosing script or an earlier run.
+    if cmp -s "$src" "$LOCKFILE"; then
+        return 0
+    fi
     if ! mkdir "$LOCKDIR" 2>/dev/null; then
         echo "Another instance is running. If you're sure it's not, remove $LOCKDIR and try again." >&2
         exit 1
diff --git a/payjoin-ffi/csharp/scripts/build_nuget_native.sh b/payjoin-ffi/csharp/scripts/build_nuget_native.sh
index 979c9aef9..6a9c94fe4 100755
--- a/payjoin-ffi/csharp/scripts/build_nuget_native.sh
+++ b/payjoin-ffi/csharp/scripts/build_nuget_native.sh
@@ -101,6 +101,12 @@ rid_to_cross_tool() {
 
 SCRIPT_DIR="$(cd "$(dirname "${BASH_SOURCE[0]}")" && pwd)"
 CSHARP_DIR="$(cd "$SCRIPT_DIR/.." && pwd)"
+
+REPO_ROOT="$(cd "$CSHARP_DIR/../.." && pwd)"
+cd "$REPO_ROOT"
+source contrib/lockfile.sh
+use_lockfile Cargo-recent.lock
+
 cd "$CSHARP_DIR"
 
 RID=${PAYJOIN_FFI_RID:-$(detect_rid)}
diff --git a/payjoin-ffi/csharp/scripts/generate_bindings.sh b/payjoin-ffi/csharp/scripts/generate_bindings.sh
index 7826fe30d..a4016c037 100755
--- a/payjoin-ffi/csharp/scripts/generate_bindings.sh
+++ b/payjoin-ffi/csharp/scripts/generate_bindings.sh
@@ -25,6 +25,12 @@ fi
 
 # Get the directory where this script is located
 SCRIPT_DIR="$(cd "$(dirname "${BASH_SOURCE[0]}")" && pwd)"
+
+REPO_ROOT="$(cd "$SCRIPT_DIR/../../.." && pwd)"
+cd "$REPO_ROOT"
+source contrib/lockfile.sh
+use_lockfile Cargo-recent.lock
+
 # Navigate to payjoin-ffi directory (parent of csharp, which is parent of scripts)
 cd "$SCRIPT_DIR/../.."
 
diff --git a/payjoin-ffi/dart/contrib/test.sh b/payjoin-ffi/dart/contrib/test.sh
index 227491e50..d248fa642 100755
--- a/payjoin-ffi/dart/contrib/test.sh
+++ b/payjoin-ffi/dart/contrib/test.sh
@@ -11,8 +11,8 @@ use_lockfile Cargo-recent.lock
 
 cd "$REPO_ROOT/payjoin-ffi/dart"
 
-echo "==> Cleaning nested Cargo.lock..."
-rm -f native/Cargo.lock
+echo "==> Seeding the nested workspace's Cargo.lock from the maintained lockfile..."
+cp "$REPO_ROOT/Cargo-recent.lock" native/Cargo.lock
 
 echo "==> Generating FFI bindings..."
 bash ./scripts/generate_bindings.sh
diff --git a/payjoin-ffi/dart/native/Cargo.toml b/payjoin-ffi/dart/native/Cargo.toml
index bf209bc2c..4a18acbe9 100644
--- a/payjoin-ffi/dart/native/Cargo.toml
+++ b/payjoin-ffi/dart/native/Cargo.toml
@@ -21,3 +21,9 @@ crate-type = ["staticlib", "cdylib"]
 payjoin-ffi = { git = "https://github.com/payjoin/rust-payjoin.git", rev = "60d0adbf4ee8e60090209d55e9864893a4acc30e", features = [
   "dart",
 ] }
+# Not used directly. yoke-derive 0.8.3 needs Rust 1.87 but declares no rust-version,
+# so consumers' fresh resolution on the toolchain above picks it. Drop once upstream fixes it.
+yoke-derive = "=0.8.2"
+
+[package.metadata.cargo-machete]
+ignored = ["yoke-derive"]
diff --git a/payjoin-ffi/javascript/scripts/generate_bindings.sh b/payjoin-ffi/javascript/scripts/generate_bindings.sh
index 31f601fab..6ff7b1b1c 100755
--- a/payjoin-ffi/javascript/scripts/generate_bindings.sh
+++ b/payjoin-ffi/javascript/scripts/generate_bindings.sh
@@ -31,6 +31,13 @@ if command -v rustup >/dev/null 2>&1 &&
     rustup target add wasm32-unknown-unknown
 fi
 
+# ubrn's generated wasm crate and the test-utils napi addon are workspaces of
+# their own; seed both from the maintained lockfile.
+JS_DIR="$(cd "$(dirname "${BASH_SOURCE[0]}")/.." && pwd)"
+mkdir -p "$JS_DIR/rust_modules/wasm"
+cp "$JS_DIR/../../Cargo-recent.lock" "$JS_DIR/rust_modules/wasm/Cargo.lock"
+cp "$JS_DIR/../../Cargo-recent.lock" "$JS_DIR/test-utils/Cargo.lock"
+
 npm run build
 
 # The test-utils addon is a dev-only native helper for the integration tests.