diff --git a/.github/workflows/ci.yml b/.github/workflows/ci.yml
index 9465406..294975b 100644
--- a/.github/workflows/ci.yml
+++ b/.github/workflows/ci.yml
@@ -79,18 +79,30 @@ jobs:
         with:
           targets: riscv64gc-unknown-linux-gnu
 
-      - name: Install cross-compilation toolchain
+      - name: Install zig
+        uses: mlugg/setup-zig@v2
+        with:
+          version: 0.16.0
+
+      - name: Install cargo-zigbuild
+        run: cargo install cargo-zigbuild --locked
+
+      # zig may print "ignoring deprecated linker optimization setting" — harmless, build still succeeds
+      - name: Build for RISC-V (glibc 2.31 floor)
+        run: cargo zigbuild --release --target riscv64gc-unknown-linux-gnu.2.31 --package riscfetch
+
+      - name: Verify glibc floor
         run: |
+          set -euo pipefail
           sudo apt-get update
-          sudo apt-get install -y gcc-riscv64-linux-gnu
+          sudo apt-get install -y binutils-riscv64-linux-gnu
+          max=$(riscv64-linux-gnu-objdump -T target/riscv64gc-unknown-linux-gnu/release/riscfetch | grep -o 'GLIBC_[0-9.]*' | sort -uV | tail -1)
+          echo "max glibc symbol: $max"
+          test "$(printf 'GLIBC_2.31\n%s\n' "$max" | sort -V | tail -1)" = "GLIBC_2.31"
 
-      - name: Configure cargo for cross-compilation
-        run: |
-          mkdir -p .cargo
-          cat >> .cargo/config.toml << 'EOF'
-          [target.riscv64gc-unknown-linux-gnu]
-          linker = "riscv64-linux-gnu-gcc"
-          EOF
-
-      - name: Build for RISC-V
-        run: cargo build --workspace --target riscv64gc-unknown-linux-gnu
+      - name: Upload artifact
+        uses: actions/upload-artifact@v4
+        with:
+          name: riscfetch-linux-riscv64
+          path: target/riscv64gc-unknown-linux-gnu/release/riscfetch
+          if-no-files-found: error
diff --git a/.github/workflows/release.yml b/.github/workflows/release.yml
index fcdaa3c..5ca2390 100644
--- a/.github/workflows/release.yml
+++ b/.github/workflows/release.yml
@@ -27,21 +27,26 @@ jobs:
         with:
           targets: riscv64gc-unknown-linux-gnu
 
-      - name: Install cross-compilation toolchain
-        run: |
-          sudo apt-get update
-          sudo apt-get install -y gcc-riscv64-linux-gnu
+      - name: Install zig
+        uses: mlugg/setup-zig@v2
+        with:
+          version: 0.16.0
 
-      - name: Configure cargo for cross-compilation
-        run: |
-          mkdir -p .cargo
-          cat >> .cargo/config.toml << 'EOF'
-          [target.riscv64gc-unknown-linux-gnu]
-          linker = "riscv64-linux-gnu-gcc"
-          EOF
+      - name: Install cargo-zigbuild
+        run: cargo install cargo-zigbuild --locked
 
-      - name: Build for RISC-V
-        run: cargo build --release --target riscv64gc-unknown-linux-gnu --package riscfetch
+      # zig may print "ignoring deprecated linker optimization setting" — harmless, build still succeeds
+      - name: Build for RISC-V (glibc 2.31 floor)
+        run: cargo zigbuild --release --target riscv64gc-unknown-linux-gnu.2.31 --package riscfetch
+
+      - name: Verify glibc floor
+        run: |
+          set -euo pipefail
+          sudo apt-get update
+          sudo apt-get install -y binutils-riscv64-linux-gnu
+          max=$(riscv64-linux-gnu-objdump -T target/riscv64gc-unknown-linux-gnu/release/riscfetch | grep -o 'GLIBC_[0-9.]*' | sort -uV | tail -1)
+          echo "max glibc symbol: $max"
+          test "$(printf 'GLIBC_2.31\n%s\n' "$max" | sort -V | tail -1)" = "GLIBC_2.31"
 
       - name: Package artifact
         run: |
diff --git a/CHANGELOG.md b/CHANGELOG.md
index 8d22b90..f1616f6 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -11,6 +11,9 @@ All notable changes to this project will be documented in this file.
 - Extension count: 147 → 151 (103 Z + 48 S)
 - Detection keywords reorganized into 3 explicit tiers (SoC identifiers → board names → vendor names) so a board name shipped across multiple SoC generations resolves to the correct SoC vendor instead of a stale one (e.g. DeepComputing DC-ROMA shipped on StarFive JH7110, then SpacemiT K3 silicon; Milk-V/Banana Pi/Sipeed ship both SpacemiT K1 and K3 boards). 5 new SoC-identifier keywords added (`spacemit,k1`, `spacemit,k3`, `sg2044`, `sg2380`, `sun20i`); detection keyword count: 42 → 47
 
+### Fixed
+- Prebuilt riscv64 binary now targets glibc 2.31 (built with cargo-zigbuild); v2.3.1's binary required glibc 2.39 and failed on Ubuntu 22.04 boards (#18)
+
 ## [2.3.1] - 2026-04-27
 
 ### Fixed
diff --git a/README.ja.md b/README.ja.md
index a256db7..fde7108 100644
--- a/README.ja.md
+++ b/README.ja.md
@@ -46,6 +46,8 @@ chmod +x riscfetch-linux-riscv64
 sudo mv riscfetch-linux-riscv64 /usr/local/bin/riscfetch
 ```
 
+glibc 2.31 以上が必要です。
+
 ## 使い方
 
 ```bash
diff --git a/README.md b/README.md
index c9a278d..76a3bcd 100644
--- a/README.md
+++ b/README.md
@@ -46,6 +46,8 @@ chmod +x riscfetch-linux-riscv64
 sudo mv riscfetch-linux-riscv64 /usr/local/bin/riscfetch
 ```
 
+Requires glibc >= 2.31.
+
 ## Usage
 
 ```bash
diff --git a/README.zh-CN.md b/README.zh-CN.md
index ee8fd88..8b3fb7c 100644
--- a/README.zh-CN.md
+++ b/README.zh-CN.md
@@ -46,6 +46,8 @@ chmod +x riscfetch-linux-riscv64
 sudo mv riscfetch-linux-riscv64 /usr/local/bin/riscfetch
 ```
 
+需要 glibc >= 2.31。
+
 ## 使用方法
 
 ```bash