diff --git a/.github/workflows/ci.yml b/.github/workflows/ci.yml
index 89a07ec..de6ca62 100644
--- a/.github/workflows/ci.yml
+++ b/.github/workflows/ci.yml
@@ -39,11 +39,11 @@ jobs:
       - name: Format
         run: cargo fmt --all -- --check
       - name: Test
-        run: cargo test --workspace
+        run: cargo test --locked --workspace
       - name: Clippy
-        run: cargo clippy --workspace --all-targets -- -D warnings
+        run: cargo clippy --locked --workspace --all-targets -- -D warnings
       - name: qfbvsmtrs fuzz crate check
-        run: cargo check --manifest-path crates/qfbvsmtrs/fuzz/Cargo.toml
+        run: cargo check --locked --manifest-path crates/qfbvsmtrs/fuzz/Cargo.toml
       - name: Python client smoke
         run: python python/tests/test_python_client.py
       - name: Python package install smoke
@@ -55,7 +55,7 @@ jobs:
       - name: C++ client CMake smoke
         shell: bash
         run: |
-          cargo build -p smt-server
+          cargo build --locked -p smt-server
           cd cpp
           cmake -B build -DCMAKE_BUILD_TYPE=Debug
           cmake --build build --config Debug
diff --git a/.github/workflows/extended.yml b/.github/workflows/extended.yml
index 3efbe58..4497611 100644
--- a/.github/workflows/extended.yml
+++ b/.github/workflows/extended.yml
@@ -26,8 +26,8 @@ jobs:
       - name: Extended random circuit identities
         env:
           QFBVSMTRS_RANDOM_CIRCUIT_SAMPLES: "10000"
-        run: cargo test -p qfbvsmtrs --test random_circuits randomized_wide_circuit_identities_production_when_enabled
+        run: cargo test --locked -p qfbvsmtrs --test random_circuits randomized_wide_circuit_identities_production_when_enabled
       - name: Extended random differential tests against z3
         env:
           QFBVSMTRS_DIFF_RANDOM: "1"
-        run: cargo test -p qfbvsmtrs --test differential_z3 differential_random_formulas_against_z3_production_when_enabled
+        run: cargo test --locked -p qfbvsmtrs --test differential_z3 differential_random_formulas_against_z3_production_when_enabled