diff --git a/ci/ci-tests.sh b/ci/ci-tests.sh
index 01ef631f783..7dad1436e98 100755
--- a/ci/ci-tests.sh
+++ b/ci/ci-tests.sh
@@ -42,6 +42,11 @@ for DIR in lightning lightning-invoice lightning-rapid-gossip-sync; do
 	RUSTFLAGS="--cfg=c_bindings" cargo test --verbose --color always --no-default-features --features=no-std
 	popd
 done
+# This one only works for lightning-invoice
+pushd lightning-invoice
+# check that compile with no-std and serde works in lightning-invoice
+cargo test --verbose --color always --no-default-features --features no-std --features serde
+popd
 
 echo -e "\n\nTesting no-std build on a downstream no-std crate"
 # check no-std compatibility across dependencies
diff --git a/lightning-invoice/src/lib.rs b/lightning-invoice/src/lib.rs
index e9565f4ce30..8426db37c64 100644
--- a/lightning-invoice/src/lib.rs
+++ b/lightning-invoice/src/lib.rs
@@ -1648,7 +1648,7 @@ impl<'de> Deserialize<'de> for Invoice {
 	fn deserialize<D>(deserializer: D) -> Result<Invoice, D::Error> where D: Deserializer<'de> {
 		let bolt11 = String::deserialize(deserializer)?
 			.parse::<Invoice>()
-			.map_err(|e| D::Error::custom(format!("{:?}", e)))?;
+			.map_err(|e| D::Error::custom(alloc::format!("{:?}", e)))?;
 
 		Ok(bolt11)
 	}