diff --git a/.github/workflows/amd64-linux-main-proof.yml b/.github/workflows/amd64-linux-main-proof.yml
index 4b49558f..2054c007 100644
--- a/.github/workflows/amd64-linux-main-proof.yml
+++ b/.github/workflows/amd64-linux-main-proof.yml
@@ -17,14 +17,19 @@ jobs:
       - name: checkout
         uses: actions/checkout@v3
 
+      - uses: DeterminateSystems/magic-nix-cache-action@v4
+
+      - name: enter nix shell
+        run: nix --experimental-features 'nix-command flakes' develop
+
       - name: extract and check
-        run: JASMIN=$(which_jasminc) EASYCRYPT=$(which_easycrypt) ECARGS=$(which_eclib) make -j$JOBS -C proof/ CI=1 default
+        run: ECARGS=$(which_eclib) make -j$JOBS -C proof/ CI=1 default
 
       - name: dist
         run: ./scripts/ci/releaser/jdist-proof
 
       - name: print logs
-        run: JASMIN=$(which_jasminc) EASYCRYPT=$(which_easycrypt) ECARGS=$(which_eclib) make         -C proof/ CI=1 reporter
+        run: ECARGS=$(which_eclib) make         -C proof/ CI=1 reporter
 
       - name: return error if there are any errors
         run: make         -C proof/ CI=1 err
diff --git a/.github/workflows/amd64-linux-main-safety.yml.0 b/.github/workflows/amd64-linux-main-safety.yml.0
index 4eb67b5e..b22ccea1 100644
--- a/.github/workflows/amd64-linux-main-safety.yml.0
+++ b/.github/workflows/amd64-linux-main-safety.yml.0
@@ -14,6 +14,11 @@ jobs:
       - name: checkout
         uses: actions/checkout@v3
 
+      - uses: DeterminateSystems/magic-nix-cache-action@v4
+
+      - name: enter nix shell
+        run: nix --experimental-features 'nix-command flakes' develop
+
       - name: compile
         run: (timeout 4300m make -j$JOBS -C src/ CI=1 SAFETY_TIMEOUT=2880m safety) || true
 
diff --git a/.github/workflows/amd64-linux-main.yml b/.github/workflows/amd64-linux-main.yml
index c447b537..8e4a8847 100644
--- a/.github/workflows/amd64-linux-main.yml
+++ b/.github/workflows/amd64-linux-main.yml
@@ -17,10 +17,15 @@ jobs:
       - name: checkout
         uses: actions/checkout@v3
 
+      - uses: DeterminateSystems/magic-nix-cache-action@v4
+
+      - name: enter nix shell
+        run: nix --experimental-features 'nix-command flakes' develop
+
       - name: compile
-        run: JASMIN=$(which_jasminc) make -j$JOBS -C src/ CI=1 default
+        run: make -j$JOBS -C src/ CI=1 default
       - name: print logs
-        run: JASMIN=$(which_jasminc) make -C src/ CI=1 reporter
+        run: make -C src/ CI=1 reporter
       - name: return error if there are any errors
         run: make -C src/ CI=1 err
 
@@ -40,10 +45,15 @@ jobs:
       - name: checkout
         uses: actions/checkout@v3
 
+      - uses: DeterminateSystems/magic-nix-cache-action@v4
+
+      - name: enter nix shell
+        run: nix --experimental-features 'nix-command flakes' develop
+
       - name: compile and run
-        run: JASMIN=$(which_jasminc) make -j$JOBS -C test/ CI=1 default
+        run: make -j$JOBS -C test/ CI=1 default
       - name: print logs
-        run: JASMIN=$(which_jasminc) make -C test/ CI=1 reporter
+        run: make -C test/ CI=1 reporter
       - name: return error if there are any errors
         run: make -C test/ CI=1 err
 
@@ -63,14 +73,19 @@ jobs:
       - name: checkout
         uses: actions/checkout@v3
 
+      - uses: DeterminateSystems/magic-nix-cache-action@v4
+
+      - name: enter nix shell
+        run: nix --experimental-features 'nix-command flakes' develop
+
       - name: compile
-        run: JASMIN=$(which_jasminc) make -j$JOBS -C src/   CI=1 default
+        run: make -j$JOBS -C src/   CI=1 default
 
       - name: run
-        run: JASMIN=$(which_jasminc) make -j$JOBS -C bench/ CI=1 DEFINE='-DTIMINGS=10' run
+        run: make -j$JOBS -C bench/ CI=1 DEFINE='-DTIMINGS=10' run
 
       - name: print logs
-        run: JASMIN=$(which_jasminc) make -C bench/ CI=1 reporter
+        run: make -C bench/ CI=1 reporter
 
       - name: return error if there are any errors
         run: make -C bench/ CI=1 err
@@ -91,14 +106,19 @@ jobs:
       - name: checkout
         uses: actions/checkout@v3
 
+      - uses: DeterminateSystems/magic-nix-cache-action@v4
+
+      - name: enter nix shell
+        run: nix --experimental-features 'nix-command flakes' develop
+
       - name: compile
-        run: JASMIN=$(which_jasminc) make -j$JOBS -C src/   CI=1 default
+        run: make -j$JOBS -C src/   CI=1 default
 
       - name: run
-        run: JASMIN=$(which_jasminc) make -j$JOBS -C bench/ CI=1 run DEFINE='-DTIMINGS=10 -DRUNS=2 -DST_ON' RANDINC='../test/common/' RANDLIB='../test/common/notrandombytes.c';
+        run: make -j$JOBS -C bench/ CI=1 run DEFINE='-DTIMINGS=10 -DRUNS=2 -DST_ON' RANDINC='../test/common/' RANDLIB='../test/common/notrandombytes.c';
 
       - name: print logs
-        run: JASMIN=$(which_jasminc) make -C bench/ CI=1 reporter
+        run: make -C bench/ CI=1 reporter
 
       - name: return error if there are any errors
         run: make -C bench/ CI=1 err
@@ -119,12 +139,17 @@ jobs:
       - name: checkout
         uses: actions/checkout@v3
 
+      - uses: DeterminateSystems/magic-nix-cache-action@v4
+
+      - name: enter nix shell
+        run: nix --experimental-features 'nix-command flakes' develop
+
       - name: extract and check
-        run: JASMIN=$(which_jasminc) EASYCRYPT=$(which_easycrypt) ECARGS=$(which_eclib) make -j$JOBS -C proof/ CI=1 check-extracted
+        run: ECARGS=$(which_eclib) make -j$JOBS -C proof/ CI=1 check-extracted
       - name: dist
         run: ./scripts/ci/releaser/jdist-proof
       - name: print logs
-        run: JASMIN=$(which_jasminc) EASYCRYPT=$(which_easycrypt) ECARGS=$(which_eclib) make -C proof/ CI=1 reporter
+        run: ECARGS=$(which_eclib) make -C proof/ CI=1 reporter
       - name: return error if there are any errors
         run: make -C proof/ CI=1 err
 
@@ -151,14 +176,19 @@ jobs:
       - name: checkout
         uses: actions/checkout@v3
 
+      - uses: DeterminateSystems/magic-nix-cache-action@v4
+
+      - name: enter nix shell
+        run: nix --experimental-features 'nix-command flakes' develop
+
       - name: compile amd64
-        run: JASMIN=$(which_jasminc) make -j$JOBS -C src/ CI=1 default
+        run: make -j$JOBS -C src/ CI=1 default
 
       - name: dist amd64
-        run: JASMIN=$(which_jasminc) ./scripts/ci/releaser/jdist-src-v1 amd64
+        run: ./scripts/ci/releaser/jdist-src-v1 amd64
 
       - name: check dist amd64
-        run: JASMIN=$(which_jasminc) ./scripts/ci/releaser/jdist-src-test-v1 amd64
+        run: ./scripts/ci/releaser/jdist-src-test-v1 amd64
 
       - name: libjade-dist-src-amd64.tar.gz - contains assembly, Jasmin, and how-to-use code
         if: always()