diff --git a/hermes/Cargo.lock b/hermes/Cargo.lock
index 38e4939e..ca9fa5eb 100644
--- a/hermes/Cargo.lock
+++ b/hermes/Cargo.lock
@@ -1764,7 +1764,7 @@ checksum = "95505c38b4572b2d910cecb0281560f54b440a19336cbbcb27bf6ce6adc6f5a8"
 
 [[package]]
 name = "hermes"
-version = "0.1.17"
+version = "0.1.18"
 dependencies = [
  "anyhow",
  "async-trait",
diff --git a/hermes/Cargo.toml b/hermes/Cargo.toml
index c1c2e971..c6432e8b 100644
--- a/hermes/Cargo.toml
+++ b/hermes/Cargo.toml
@@ -1,6 +1,6 @@
 [package]
 name    = "hermes"
-version = "0.1.17"
+version = "0.1.18"
 edition = "2021"
 
 [dependencies]
diff --git a/hermes/shell.nix b/hermes/shell.nix
index ba2e2ee6..6721578f 100644
--- a/hermes/shell.nix
+++ b/hermes/shell.nix
@@ -8,14 +8,16 @@ with pkgs; mkShell {
     llvmPackages.libclang
     nettle
     openssl_1_1
-    pkgconfig
+    pkg-config
     iconv
     protobuf
     go
     rustup
+    curl
   ];
 
   shellHook = ''
     export LIBCLANG_PATH="${llvmPackages.libclang.lib}/lib";
+    export CPATH="${darwin.Libsystem}/include";
   '';
 }
diff --git a/hermes/src/aggregate.rs b/hermes/src/aggregate.rs
index c418036c..c1a1def4 100644
--- a/hermes/src/aggregate.rs
+++ b/hermes/src/aggregate.rs
@@ -211,7 +211,8 @@ pub async fn store_update(state: &State, update: Update) -> Result<()> {
         let mut aggregate_state = state.aggregate_state.write().await;
         aggregate_state.latest_observed_slot = aggregate_state
             .latest_observed_slot
-            .map(|latest| latest.max(slot));
+            .map(|latest| latest.max(slot))
+            .or(Some(slot));
     }
 
     let accumulator_messages = state.fetch_accumulator_messages(slot).await?;
@@ -260,7 +261,8 @@ pub async fn store_update(state: &State, update: Update) -> Result<()> {
 
     aggregate_state.latest_completed_slot = aggregate_state
         .latest_completed_slot
-        .map(|latest| latest.max(slot));
+        .map(|latest| latest.max(slot))
+        .or(Some(slot));
 
     aggregate_state
         .latest_completed_update_at