diff --git a/ci/test_full.sh b/ci/test_full.sh
index 6cafcc5..60e9740 100755
--- a/ci/test_full.sh
+++ b/ci/test_full.sh
@@ -38,6 +38,14 @@ cargo generate-lockfile
 # libm 0.2.6 started using {float}::EPSILON
 check_version 1.43 || cargo update -p libm --precise 0.2.5
 
+# Some crates moved to Rust 1.56 / 2021
+check_version 1.56 || (
+  cargo update -p quote --precise 1.0.30
+  cargo update -p proc-macro2 --precise 1.0.65
+  cargo update -p rkyv --precise 0.7.40
+  cargo update -p bytecheck --precise 0.6.9
+)
+
 set -x
 
 # test the default