diff --git a/update_cached_hashes.sh b/update_cached_hashes.sh
index fe73e29..8f0d54b 100755
--- a/update_cached_hashes.sh
+++ b/update_cached_hashes.sh
@@ -1,22 +1,62 @@
 #!/usr/bin/env bash
 
-# this guy updates the hash of the last
-# successful build of nixpkgs on hydra
-# (so we don't have to rebuild EVERYTHING)
 RELEASE=24.11
 
-set -e
+update_channel() {
+	local channel_name="$1"     # Hydra channel name (e.g., nixos-24.11)
+	local flake_input_name="$2" # Flake input name (e.g., nixpkgs)
+	local new old
 
-new=$(curl -sL "https://monitoring.nixos.org/prometheus/api/v1/query?query=channel_revision" | jq -r ".data.result[] | select(.metric.channel==\"nixos-${RELEASE}\") | .metric.revision")
-old=$(jq -r '.nodes as $nodes | .nodes.root.inputs.nixpkgs as $tgt_nixpkgs | $nodes | to_entries[] | select(.key == $tgt_nixpkgs) | .value.locked.rev' flake.lock)
+	# Get latest revision from Hydra
+	new=$(curl -sL "https://monitoring.nixos.org/prometheus/api/v1/query?query=channel_revision" |
+		jq -r ".data.result[] | select(.metric.channel==\"${channel_name}\") | .metric.revision")
 
-if [ "${old}" != "${new}" ]; then
-  echo "Old hash: ${old}"
-  echo "New hash: ${new}"
+	# Get current revision from flake.lock using input name
+	old=$(jq -r ".nodes as \$nodes | 
+                .nodes.root.inputs.[\"${flake_input_name}\"] as \$target_input |
+                \$nodes | to_entries[] | 
+                select(.key == \$target_input) | 
+                .value.locked.rev" flake.lock)
 
-  sed -i s/"${old}"/"${new}"/ flake.nix
+	if [ "${old}" == "${new}" ]; then
+		return
+	fi
 
-  exit
-fi
+	replace_hash "${flake_input_name}" "${new}"
 
-echo "No updates available."
+	echo "${new}"
+}
+
+replace_hash() {
+	local name="$1" hash="$2"
+
+  sed -i "s|\(${name}\.url = \"github:NixOS/nixpkgs/\)[^\"]*|\1${hash}|" flake.nix
+	# sed -i "s|${name}/${old}|${name}/${new}|" flake.nix
+}
+
+update_stable() {
+	echo "Checking NixOS ${RELEASE}..."
+
+	new_hash=$(update_channel "nixos-${RELEASE}" "nixpkgs")
+
+	if [ -z "$new_hash" ]; then
+		return
+	fi
+
+	echo "Updated stable to: ${new_hash}"
+}
+
+update_unstable() {
+	echo "Checking unstable..."
+
+	new_hash=$(update_channel "nixpkgs-unstable" "nixpkgs-unstable")
+
+	if [ -z "$new_hash" ]; then
+		return
+	fi
+
+	echo "Updated unstable to: ${new_hash}"
+}
+
+update_stable
+update_unstable