diff --git a/.github/workflows/ci.yaml b/.github/workflows/ci.yaml
index 853060601..005509db0 100644
--- a/.github/workflows/ci.yaml
+++ b/.github/workflows/ci.yaml
@@ -47,6 +47,7 @@ jobs:
       - uses: dtolnay/rust-toolchain@1.31.0
         with:
           target: thumbv6m-none-eabi
+      - run: cargo generate-lockfile && cargo update -p libm --precise 0.2.5
       - run: cargo build --target thumbv6m-none-eabi --no-default-features --features "libm"
 
   fmt:
diff --git a/ci/test_full.sh b/ci/test_full.sh
index 5b5bef3f1..f43635be9 100755
--- a/ci/test_full.sh
+++ b/ci/test_full.sh
@@ -37,6 +37,11 @@ if [ -n "${ALLOC_FEATURES[*]}" ]; then
   echo "  alloc supported features: ${ALLOC_FEATURES[*]}"
 fi
 
+cargo generate-lockfile
+
+# libm 0.2.6 started using {float}::EPSILON
+check_version 1.43 || cargo update -p libm --precise 0.2.5
+
 set -x
 
 # test the default with std