diff --git a/contrib/test.sh b/contrib/test.sh
index e76c193..379059e 100755
--- a/contrib/test.sh
+++ b/contrib/test.sh
@@ -1,7 +1,8 @@
-#!/bin/sh
+#!/usr/bin/env bash
 
 set -ex
 
+REPO_DIR=$(git rev-parse --show-toplevel)
 FEATURES="bitcoin-hashes global-context lowmemory rand recovery serde std alloc bitcoin-hashes-std rand-std"
 
 cargo --version
@@ -16,11 +17,13 @@ fi
 # Pin dependencies as required if we are using MSRV toolchain.
 if cargo --version | grep "1\.48"; then
     cargo update -p wasm-bindgen-test --precise 0.3.34
-    cargo update -p serde --precise 1.0.156
+    cargo update -p serde_test --precise 1.0.175
 fi
 
 # Test if panic in C code aborts the process (either with a real panic or with SIGILL)
-cargo test -- --ignored --exact 'tests::test_panic_raw_ctx_should_terminate_abnormally' 2>&1 | tee /dev/stderr | grep "SIGILL\\|panicked at '\[libsecp256k1\]"
+cargo test -- --ignored --exact 'tests::test_panic_raw_ctx_should_terminate_abnormally' 2>&1 \
+    | tee /dev/stderr \
+    | grep "SIGILL\\|\[libsecp256k1] illegal argument. !rustsecp256k1_v0_._._fe_is_zero(&ge->x)"
 
 # Make all cargo invocations verbose
 export CARGO_TERM_VERBOSE=true
@@ -106,6 +109,12 @@ if [ "$DO_ASAN" = true ]; then
     CC='clang -fsanitize=memory -fno-omit-frame-pointer'                                                                        \
     RUSTFLAGS='-Zsanitizer=memory -Zsanitizer-memory-track-origins -Cforce-frame-pointers=yes -Cllvm-args=-msan-eager-checks=0' \
     cargo test --lib --all --features="$FEATURES" -Zbuild-std --target x86_64-unknown-linux-gnu
+
+    pushd "$REPO_DIR/no_std_test" > /dev/null || exit 1
+    # See https://github.com/rust-bitcoin/rust-secp256k1/pull/641#issuecomment-1671598914
+    cargo update -p cc --precise 1.0.79
+    popd > /dev/null || exit 1
+
     cargo run --release --manifest-path=./no_std_test/Cargo.toml | grep -q "Verified Successfully"
     cargo run --release --features=alloc --manifest-path=./no_std_test/Cargo.toml | grep -q "Verified alloc Successfully"
 fi
diff --git a/no_std_test/src/main.rs b/no_std_test/src/main.rs
index d98276c..2e2a3bd 100644
--- a/no_std_test/src/main.rs
+++ b/no_std_test/src/main.rs
@@ -27,7 +27,6 @@
 //!     * Requires linking with `libc` for calling `printf`.
 //!
 
-#![feature(lang_items)]
 #![feature(start)]
 #![feature(core_intrinsics)]
 #![feature(panic_info_message)]
diff --git a/src/key.rs b/src/key.rs
index 0eb747e..ecec179 100644
--- a/src/key.rs
+++ b/src/key.rs
@@ -1036,6 +1036,8 @@ impl serde::Serialize for KeyPair {
 }
 
 #[cfg(feature = "serde")]
+#[allow(unused_variables)] // For `data` under some feature combinations (the unconditional panic below).
+#[allow(unreachable_code)] // For `KeyPair::from_seckey_slice` after unconditional panic.
 impl<'de> serde::Deserialize<'de> for KeyPair {
     fn deserialize<D: serde::Deserializer<'de>>(d: D) -> Result<Self, D::Error> {
         if d.is_human_readable() {
@@ -1051,7 +1053,7 @@ impl<'de> serde::Deserialize<'de> for KeyPair {
                 let ctx = Secp256k1::signing_only();
 
                 #[cfg(not(any(feature = "global-context", feature = "alloc")))]
-                let ctx: Secp256k1<crate::SignOnlyPreallocated> = panic!("The previous implementation was panicking too, please enable the global-context feature of rust-secp256k1");
+                let ctx: Secp256k1<crate::SignOnlyPreallocated> = panic!("cannot deserialize key pair without a context (please enable either the global-context or alloc feature)");
 
                 #[allow(clippy::needless_borrow)]
                 KeyPair::from_seckey_slice(&ctx, data)