diff --git a/nix/agent-modules/default.nix b/nix/agent-modules/default.nix
index 5db3dbdc..6047ad5c 100644
--- a/nix/agent-modules/default.nix
+++ b/nix/agent-modules/default.nix
@@ -242,7 +242,7 @@ in
     ++ [
       (
         if config.services.hyperhive.agent.claudeCodePath == null then
-          pkgs.claude-code
+          import ../claude-code-no-alsa.nix lib pkgs.claude-code
         else
           # Host-pinned claude: a symlink farm around a path the
           # container was handed as text. It has to be a derivation —
diff --git a/nix/claude-code-no-alsa.nix b/nix/claude-code-no-alsa.nix
new file mode 100644
index 00000000..89484a11
--- /dev/null
+++ b/nix/claude-code-no-alsa.nix
@@ -0,0 +1,25 @@
+# `claude-code` without the `--prefix LD_LIBRARY_PATH` alsa-lib entry
+# nixpkgs adds to its wrapper. The wrapper exports the variable into
+# claude's own environment, so every shell claude spawns inherits an
+# alsa-lib `lib` dir that shadows the libraries newer nixpkgs binaries
+# (headless chromium) were built against. Agents have no audio device,
+# so alsa-lib is not needed. Every other wrapper flag stays.
+#
+# nixpkgs gives no switch for it (`alsa-lib` only feeds that one
+# `makeLibraryPath`), so the line is dropped from `installPhase`. A
+# package whose `installPhase` has no such line comes back unchanged.
+lib: claudeCode:
+let
+  marker = "--prefix LD_LIBRARY_PATH";
+  dropMarker =
+    phase:
+    lib.concatStringsSep "\n" (
+      builtins.filter (l: !(lib.hasInfix marker l)) (lib.splitString "\n" phase)
+    );
+in
+if lib.hasInfix marker (claudeCode.installPhase or "") then
+  claudeCode.overrideAttrs (old: {
+    installPhase = dropMarker old.installPhase;
+  })
+else
+  claudeCode
diff --git a/nix/host-modules/hive-c0re/default.nix b/nix/host-modules/hive-c0re/default.nix
index 0e87c4bf..056cdb92 100644
--- a/nix/host-modules/hive-c0re/default.nix
+++ b/nix/host-modules/hive-c0re/default.nix
@@ -109,7 +109,11 @@ let
     # anything that drops it. The failure mode is a garbage-collected
     # `claude` and a hive that can't take a turn, weeks after the commit
     # that caused it.
-    claude_code_path = controllerCfg.claudeCodePackage;
+    claude_code_path =
+      if controllerCfg.claudeCodePackage == null then
+        null
+      else
+        import ../../claude-code-no-alsa.nix lib controllerCfg.claudeCodePackage;
     dashboard_port = controllerCfg.dashboardPort;
     agent_cpu_quota = cfg.agentCpuQuota;
     agent_memory_max = cfg.agentMemoryMax;