diff --git a/Makefile b/Makefile
index 1aa9d25..e32decb 100644
--- a/Makefile
+++ b/Makefile
@@ -43,7 +43,7 @@
 	rustup component add clippy
 	rustup component add rustfmt
 	rustup component add miri
-	cargo install elf2tab --version 0.4.0
+	cargo install elf2tab --version 0.6.0
 	cargo install stack-sizes
 	cargo miri setup
 
diff --git a/test_runner/Cargo.toml b/test_runner/Cargo.toml
index 133ff23..66a407a 100644
--- a/test_runner/Cargo.toml
+++ b/test_runner/Cargo.toml
@@ -11,7 +11,10 @@
 futures = "0.3.4"
 
 [dependencies.async-std]
-version = "1.5.0"
+# async-std 1.7 pulls in crossbeam_utils 1.8, which does not work with the
+# nightly Rust toolchain we use. Temporarily block async-std 1.7 until we can
+# update our Rust toolchain.
+version = "1.5.0, <1.7"
 features = ["attributes"]
 
 [dependencies.tokio]