diff --git a/.github/workflows/ci.yml b/.github/workflows/ci.yml
index 372359c6..1a846e9b 100644
--- a/.github/workflows/ci.yml
+++ b/.github/workflows/ci.yml
@@ -1031,6 +1031,47 @@ jobs:
             mvn -B -q -f examples/java exec:exec -Dexec.mainClass="org.wickra.examples.$cls"
           done
 
+  # Build a Python wheel inside both the manylinux and the musllinux container,
+  # mirroring the Linux wheel build in release.yml. The 3-OS Python jobs build
+  # natively on the runner, which already ships system OpenSSL, so they cannot
+  # catch a build-time gap that only exists inside the slim release containers —
+  # exactly what broke the 0.9.3 Linux wheels (the live-binance data layer links
+  # native-tls -> openssl-sys, and the containers provide no OpenSSL: manylinux
+  # lacks the headers, musllinux cross-compiles against a musl sysroot without
+  # OpenSSL at all). The wheels are built with the `vendored-tls` feature, which
+  # statically compiles OpenSSL from source. This job exercises both container
+  # builds on every PR, so the same class of breakage now fails CI, not release.
+  python-wheel-container-smoke:
+    name: Python wheel (${{ matrix.manylinux }} smoke)
+    runs-on: ubuntu-latest
+    timeout-minutes: 30 # backstop: vendored OpenSSL adds a from-source compile
+    strategy:
+      fail-fast: false
+      matrix:
+        manylinux: [auto, musllinux_1_2]
+    steps:
+      - uses: actions/checkout@df4cb1c069e1874edd31b4311f1884172cec0e10 # v6.0.3
+        with:
+          persist-credentials: false
+
+      - name: Sync root README into bindings/python so the build matches release
+        run: cp README.md bindings/python/README.md
+
+      - uses: PyO3/maturin-action@e83996d129638aa358a18fbd1dfb82f0b0fb5d3b # v1.51.0
+        with:
+          working-directory: bindings/python
+          target: x86_64
+          # Keep in sync with release.yml: vendored OpenSSL for the Linux wheels.
+          args: --release --out dist --features vendored-tls
+          manylinux: ${{ matrix.manylinux }}
+          # Building OpenSSL from source needs Perl modules (IPC::Cmd,
+          # Time::Piece, ...) the minimal manylinux (CentOS 7) image lacks.
+          # perl-core pulls the full distribution; the explicit names document
+          # the ones OpenSSL's Configure has required. The musllinux cross image
+          # ships a complete Perl and has no yum, so this is a no-op there.
+          before-script-linux: |
+            if command -v yum >/dev/null 2>&1; then yum install -y perl-core perl-IPC-Cmd perl-Data-Dumper perl-Time-Piece; fi
+
   # The cross-library benchmark has moved to a dedicated scheduled workflow
   # (.github/workflows/bench.yml) — see audit finding R10. It runs nightly
   # at 03:00 UTC and on-demand via `workflow_dispatch`, and is no longer on
diff --git a/.github/workflows/release.yml b/.github/workflows/release.yml
index 5ca11109..be6aebc4 100644
--- a/.github/workflows/release.yml
+++ b/.github/workflows/release.yml
@@ -184,16 +184,22 @@ jobs:
         with:
           working-directory: bindings/python
           target: ${{ matrix.target }}
-          args: --release --strip --out dist
-          manylinux: ${{ matrix.manylinux }}
           # The live-binance data layer links native-tls -> openssl-sys, which
-          # needs the system OpenSSL headers at build time. The manylinux and
-          # musllinux build containers do not ship them, so install them inside
-          # the container before maturin compiles the wheel (no-op on the native
-          # macOS/Windows runners, where this hook does not run).
+          # needs OpenSSL at build time. The manylinux containers lack the headers
+          # and the musllinux build cross-compiles against a musl sysroot with no
+          # OpenSSL at all, so build the Linux wheels with vendored OpenSSL
+          # (compiled from source, linked statically). No-op on the native
+          # macOS/Windows runners, where native-tls never pulls openssl-sys. The
+          # CI `python-wheel-container-smoke` job exercises both containers on PRs.
+          args: --release --strip --out dist --features vendored-tls
+          manylinux: ${{ matrix.manylinux }}
+          # Building OpenSSL from source needs Perl modules (IPC::Cmd,
+          # Time::Piece, ...) the minimal manylinux (CentOS 7) image lacks.
+          # perl-core pulls the full distribution; the explicit names document
+          # the ones OpenSSL's Configure has required. The musllinux cross image
+          # ships a complete Perl and has no yum, so this is a no-op there.
           before-script-linux: |
-            if command -v yum >/dev/null 2>&1; then yum install -y openssl-devel; fi
-            if command -v apk >/dev/null 2>&1; then apk add --no-cache openssl-dev pkgconfig; fi
+            if command -v yum >/dev/null 2>&1; then yum install -y perl-core perl-IPC-Cmd perl-Data-Dumper perl-Time-Piece; fi
       - uses: actions/upload-artifact@043fb46d1a93c77aae656e7c1c64a875d1fc6a0a # v7.0.1
         with:
           # Include manylinux in the name so the glibc and musl x86_64/aarch64
diff --git a/CHANGELOG.md b/CHANGELOG.md
index 45987cf5..a5186b0e 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -9,18 +9,28 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
 
 ## [0.9.4] - 2026-06-17
 
-Packaging fix for the `0.9.3` data layer. No library code changed; `0.9.4` is
-identical to `0.9.3` on every platform that already published. The Linux Python
-wheels are released for the first time here, because `0.9.3` could not build them.
+Packaging fix for the `0.9.3` data layer. The library is identical to `0.9.3` on
+every platform that already published; the only additions are an opt-in
+`vendored-tls` build feature and the Linux Python wheels, which `0.9.3` could not
+build.
 
 ### Fixed
 - **Linux Python wheels (`manylinux` / `musllinux`) now build.** The `live-binance`
-  data layer links `native-tls`, which pulls in `openssl-sys`, and the wheel build
-  containers do not ship the system OpenSSL headers. The release workflow now
-  installs them inside the container before compiling (`openssl-devel` on
-  `manylinux`, `openssl-dev` on `musllinux`). The native macOS and Windows wheels
-  were unaffected. As a result `0.9.3` shipped to crates.io, Maven Central, NuGet,
-  and npm but not to PyPI; PyPI publishes starting with `0.9.4`.
+  data layer links `native-tls` -> `openssl-sys`, which needs OpenSSL at build
+  time. The `manylinux` wheel containers ship no OpenSSL headers and the
+  `musllinux` build cross-compiles against a musl sysroot that has no OpenSSL at
+  all, so the wheels failed to compile. The Linux wheels are now built with a new
+  opt-in `vendored-tls` feature that compiles OpenSSL from source and links it
+  statically (no system OpenSSL required, on either libc). The native macOS and
+  Windows wheels were unaffected (Security.framework / SChannel). As a result
+  `0.9.3` shipped to crates.io, Maven Central, NuGet, and npm but not to PyPI;
+  PyPI publishes starting with `0.9.4`.
+
+### Added
+- **`vendored-tls` feature** on `wickra-data` (and the Python binding): builds the
+  `live-binance` TLS stack against a statically compiled OpenSSL. Off by default;
+  used by the release wheels and exercised on every PR by a `manylinux` /
+  `musllinux` container build-smoke CI job.
 
 
 ## [0.9.3] - 2026-06-17
diff --git a/Cargo.lock b/Cargo.lock
index 021aff92..7d4b350c 100644
--- a/Cargo.lock
+++ b/Cargo.lock
@@ -907,6 +907,15 @@ version = "0.2.1"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "7c87def4c32ab89d880effc9e097653c8da5d6ef28e6b539d313baaacfbafcbe"
 
+[[package]]
+name = "openssl-src"
+version = "300.5.4+3.5.4"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "a507b3792995dae9b0df8a1c1e3771e8418b7c2d9f0baeba32e6fe8b06c7cb72"
+dependencies = [
+ "cc",
+]
+
 [[package]]
 name = "openssl-sys"
 version = "0.9.116"
@@ -915,6 +924,7 @@ checksum = "f28a22dc7140cda5f096e5e7724a6962ca81a7f8bfd2979f9b18c11af56318c4"
 dependencies = [
  "cc",
  "libc",
+ "openssl-src",
  "pkg-config",
  "vcpkg",
 ]
diff --git a/bindings/python/Cargo.toml b/bindings/python/Cargo.toml
index be6dcea7..4336c317 100644
--- a/bindings/python/Cargo.toml
+++ b/bindings/python/Cargo.toml
@@ -17,6 +17,13 @@ publish = false
 name = "_wickra"
 crate-type = ["cdylib"]
 
+[features]
+# Build the bundled data layer against a statically compiled OpenSSL. The
+# release workflow (and the manylinux/musllinux CI smoke job) enable this so the
+# Linux wheels do not depend on system OpenSSL at build time. See the
+# `vendored-tls` feature in wickra-data for the rationale.
+vendored-tls = ["wickra-data/vendored-tls"]
+
 [lints]
 workspace = true
 
diff --git a/crates/wickra-data/Cargo.toml b/crates/wickra-data/Cargo.toml
index bea33f7a..5c9bbe5e 100644
--- a/crates/wickra-data/Cargo.toml
+++ b/crates/wickra-data/Cargo.toml
@@ -54,6 +54,15 @@ default = []
 # want. `live-binance` covers both the live WebSocket feed and the historical
 # REST kline fetcher.
 live-binance = ["dep:tokio", "dep:tokio-tungstenite", "dep:futures-util", "dep:url", "dep:ureq", "dep:native-tls"]
+# `live-binance` with a statically built OpenSSL instead of the system one. The
+# native-tls stack (tokio-tungstenite + ureq, unified on the same `native-tls`
+# crate) links `openssl-sys`, which needs OpenSSL at build time. The manylinux
+# and musllinux wheel containers do not provide it — manylinux lacks the headers
+# and the musllinux build cross-compiles against a musl sysroot that has no
+# OpenSSL at all — so the Linux wheels are built with this feature, which
+# compiles OpenSSL from source and links it statically. No-op on macOS/Windows,
+# where native-tls uses Security.framework / SChannel and never pulls openssl-sys.
+vendored-tls = ["live-binance", "native-tls/vendored"]
 
 [dev-dependencies]
 approx = { workspace = true }