diff --git a/.github/workflows/ci.yml b/.github/workflows/ci.yml
index 6feb2f3..92877f2 100644
--- a/.github/workflows/ci.yml
+++ b/.github/workflows/ci.yml
@@ -36,16 +36,23 @@ jobs:
         shell: bash
     steps:
       - uses: actions/checkout@v6
-      - name: install mach
+      # until a 7.x release exists, std is tested with the compiler built from
+      # mach's dev branch, since the released seed cannot read its manifest keys
+      - name: build mach from its dev branch
         run: |
-          export MACH_INSTALL_DIR="$RUNNER_TEMP/mach"
+          export MACH_INSTALL_DIR="$RUNNER_TEMP/seed"
           url="https://raw.githubusercontent.com/briar-systems/mach/v$MACH_VERSION/dist"
+          exe=
           if [ "$RUNNER_OS" = Windows ]; then
             pwsh -NoProfile -Command "irm $url/install.ps1 | iex"
+            exe=.exe
           else
             curl -fsSL "$url/install.sh" | sh
           fi
-          echo "$MACH_INSTALL_DIR" >> "$GITHUB_PATH"
+          git clone --quiet --depth 1 --branch dev https://github.com/briar-systems/mach "$RUNNER_TEMP/mach-src"
+          mkdir -p "$RUNNER_TEMP/mach"
+          (cd "$RUNNER_TEMP/mach-src" && bash .github/scripts/seed-build.sh "$MACH_INSTALL_DIR/mach$exe" "$RUNNER_TEMP/mach/mach$exe")
+          echo "$RUNNER_TEMP/mach" >> "$GITHUB_PATH"
       - run: mach dep pull .
       - if: strategy.job-index == 0
         run: mach fmt --check .
diff --git a/dep/std b/dep/std
index ba2b27c..6bf8512 160000
--- a/dep/std
+++ b/dep/std
@@ -1 +1 @@
-Subproject commit ba2b27c9fa62f6022032f0ddb231b15b8ef578f7
+Subproject commit 6bf851234d1abb76885967b337b1040397086ff2
diff --git a/mach.toml b/mach.toml
index b44b2c6..e1cdebc 100644
--- a/mach.toml
+++ b/mach.toml
@@ -1,9 +1,9 @@
 [project]
 id = "math"
 version = "0.1.0"
-mach = "^6.10"
+mach = "^6"
 src = "src"
-out = "out/{target.name}/{profile.name}"
+work = "out/{target.name}/{profile.name}"
 
 [target.linux-x86_64]
 isa = "x86_64"
@@ -34,8 +34,9 @@ abi = "aapcs64"
 [artifact.math]
 kind = "static"
 default = true
+export = true
 entry = "lib/math.mach"
-out = "lib/math"
+out = "{project.work}/lib/math"
 targets = ["*"]
 link = ["kernel32"]
 need = []
@@ -50,19 +51,15 @@ export = false
 
 [profile.debug]
 default = true
-opt = 0
+optimize = false
 debug = true
 simd = "scalarize"
-vectorize = false
-float_reassoc = false
 
 [profile.release]
-opt = 2
+optimize = true
 debug = false
 simd = "scalarize"
-vectorize = true
-float_reassoc = false
 
 [dep.std]
 git = "https://github.com/briar-systems/mach-std"
-version = "^9.5"
+ref = "branch/dev"