diff --git a/.cargo/config.toml b/.cargo/config.toml
index 7ec6f88e6..15fd75d2a 100644
--- a/.cargo/config.toml
+++ b/.cargo/config.toml
@@ -2,5 +2,11 @@
 # browser backend on wasm32-unknown-unknown, alongside its `wasm_js` feature
 # (enabled in Cargo.toml for the wasm target). Without it the web build fails
 # with "wasm32-unknown-unknown targets are not supported by default".
+#
+# `-Cstrip=none` overrides the release profile's `strip = true` for the wasm
+# target only: stripping removes the `target_features` custom section, so
+# `wasm-opt` can no longer see that `bulk-memory` is enabled and rejects the
+# module's memory.fill/copy ops ("require bulk memory"). Native release binaries
+# stay stripped; only the wasm keeps its feature section.
 [target.wasm32-unknown-unknown]
-rustflags = ['--cfg', 'getrandom_backend="wasm_js"']
+rustflags = ['--cfg', 'getrandom_backend="wasm_js"', '-Cstrip=none']