diff --git a/src/internet_identity/src/http/metrics.rs b/src/internet_identity/src/http/metrics.rs
index d923565488..3b166e242d 100644
--- a/src/internet_identity/src/http/metrics.rs
+++ b/src/internet_identity/src/http/metrics.rs
@@ -103,7 +103,7 @@ fn encode_metrics(w: &mut MetricsEncoder<Vec<u8>>) -> std::io::Result<()> {
     #[cfg(target_arch = "wasm32")]
     w.encode_gauge(
         "internet_identity_heap_memory_bytes",
-        (core::arch::wasm32::memory_size::<0>() * WASM_PAGE_SIZE_IN_BYTES) as f64,
+        (core::arch::wasm32::memory_size::<0>() as u64 * WASM_PAGE_SIZE_IN_BYTES) as f64,
         "Size of the heap memory allocated by this canister.",
     )?;
     w.encode_gauge(