diff --git a/ci/Dockerfile.arch b/ci/Dockerfile.arch
index 7f1088b1..55516871 100644
--- a/ci/Dockerfile.arch
+++ b/ci/Dockerfile.arch
@@ -2,6 +2,9 @@ FROM archlinux:latest
 
 ENV TERM=xterm
 ENV CC="ccache gcc"
+# Arch ships a stripped ld-linux; Valgrind needs glibc debug symbols to
+# redirect memcmp/memcpy/strlen. debuginfod fetches them on demand.
+ENV DEBUGINFOD_URLS=https://debuginfod.archlinux.org
 
 RUN pacman -Syyu --noconfirm