diff --git a/.devcontainer/Dockerfile b/.devcontainer/Dockerfile
index 2c99c9a..cdfad53 100644
--- a/.devcontainer/Dockerfile
+++ b/.devcontainer/Dockerfile
@@ -26,7 +26,7 @@ RUN apt-get update \
 
 # Full EigenScript source at the pinned tag; build the gfx variant (SDL2 is
 # dlopen'd, so building needs no -dev headers). stdlib resolves at ../lib.
-ARG EIGS_REF=v0.40.0
+ARG EIGS_REF=v0.41.0
 RUN git clone --depth 1 --branch "${EIGS_REF}" \
         https://github.com/InauguralSystems/EigenScript.git /opt/eigenscript \
  && make -C /opt/eigenscript gfx CC=gcc
diff --git a/CLAUDE.md b/CLAUDE.md
index d7edf8f..432aa5c 100644
--- a/CLAUDE.md
+++ b/CLAUDE.md
@@ -23,7 +23,7 @@ and Tidepool.
 
 ## Toolchain
 
-EigenScript is **not** vendored. Pin **v0.13.0 minimum**; **v0.40.0**
+EigenScript is **not** vendored. Pin **v0.13.0 minimum**; **v0.41.0**
 is the current tested release (`.devcontainer/Dockerfile` `EIGS_REF`).
 Two binaries matter: