diff --git a/beacon_node/http_api/src/lib.rs b/beacon_node/http_api/src/lib.rs
index 8c3902fcd4d..159a3d2f041 100644
--- a/beacon_node/http_api/src/lib.rs
+++ b/beacon_node/http_api/src/lib.rs
@@ -388,12 +388,10 @@ pub fn serve<T: BeaconChainTypes>(
     let beacon_states_path = eth1_v1
         .and(warp::path("beacon"))
         .and(warp::path("states"))
-        .and(warp::path::param::<StateId>().or_else(|_| {
-            blocking_task(|| {
-                Err(warp_utils::reject::custom_bad_request(
-                    "Invalid state ID".to_string(),
-                ))
-            })
+        .and(warp::path::param::<StateId>().or_else(|_| async {
+            Err(warp_utils::reject::custom_bad_request(
+                "Invalid state ID".to_string(),
+            ))
         }))
         .and(chain_filter.clone());
 
@@ -551,7 +549,11 @@ pub fn serve<T: BeaconChainTypes>(
     let get_beacon_state_validators_id = beacon_states_path
         .clone()
         .and(warp::path("validators"))
-        .and(warp::path::param::<ValidatorId>())
+        .and(warp::path::param::<ValidatorId>().or_else(|_| async {
+            Err(warp_utils::reject::custom_bad_request(
+                "Invalid validator ID".to_string(),
+            ))
+        }))
         .and(warp::path::end())
         .and_then(
             |state_id: StateId, chain: Arc<BeaconChain<T>>, validator_id: ValidatorId| {
@@ -760,7 +762,11 @@ pub fn serve<T: BeaconChainTypes>(
     let get_beacon_headers_block_id = eth1_v1
         .and(warp::path("beacon"))
         .and(warp::path("headers"))
-        .and(warp::path::param::<BlockId>())
+        .and(warp::path::param::<BlockId>().or_else(|_| async {
+            Err(warp_utils::reject::custom_bad_request(
+                "Invalid block ID".to_string(),
+            ))
+        }))
         .and(warp::path::end())
         .and(chain_filter.clone())
         .and_then(|block_id: BlockId, chain: Arc<BeaconChain<T>>| {
@@ -845,7 +851,11 @@ pub fn serve<T: BeaconChainTypes>(
     let beacon_blocks_path = eth1_v1
         .and(warp::path("beacon"))
         .and(warp::path("blocks"))
-        .and(warp::path::param::<BlockId>())
+        .and(warp::path::param::<BlockId>().or_else(|_| async {
+            Err(warp_utils::reject::custom_bad_request(
+                "Invalid block ID".to_string(),
+            ))
+        }))
         .and(chain_filter.clone());
 
     // GET beacon/blocks/{block_id}
@@ -1222,7 +1232,11 @@ pub fn serve<T: BeaconChainTypes>(
         .and(warp::path("debug"))
         .and(warp::path("beacon"))
         .and(warp::path("states"))
-        .and(warp::path::param::<StateId>())
+        .and(warp::path::param::<StateId>().or_else(|_| async {
+            Err(warp_utils::reject::custom_bad_request(
+                "Invalid state ID".to_string(),
+            ))
+        }))
         .and(warp::path::end())
         .and(chain_filter.clone())
         .and_then(|state_id: StateId, chain: Arc<BeaconChain<T>>| {
@@ -1531,7 +1545,11 @@ pub fn serve<T: BeaconChainTypes>(
         .and(warp::path("validator"))
         .and(warp::path("duties"))
         .and(warp::path("proposer"))
-        .and(warp::path::param::<Epoch>())
+        .and(warp::path::param::<Epoch>().or_else(|_| async {
+                Err(warp_utils::reject::custom_bad_request(
+                    "Invalid epoch".to_string(),
+                ))
+        }))
         .and(warp::path::end())
         .and(not_while_syncing_filter.clone())
         .and(chain_filter.clone())
@@ -1596,7 +1614,11 @@ pub fn serve<T: BeaconChainTypes>(
     let get_validator_blocks = eth1_v1
         .and(warp::path("validator"))
         .and(warp::path("blocks"))
-        .and(warp::path::param::<Slot>())
+        .and(warp::path::param::<Slot>().or_else(|_| async {
+            Err(warp_utils::reject::custom_bad_request(
+                "Invalid slot".to_string(),
+            ))
+        }))
         .and(warp::path::end())
         .and(not_while_syncing_filter.clone())
         .and(warp::query::<api_types::ValidatorBlocksQuery>())
@@ -1683,7 +1705,11 @@ pub fn serve<T: BeaconChainTypes>(
         .and(warp::path("validator"))
         .and(warp::path("duties"))
         .and(warp::path("attester"))
-        .and(warp::path::param::<Epoch>())
+        .and(warp::path::param::<Epoch>().or_else(|_| async {
+            Err(warp_utils::reject::custom_bad_request(
+                "Invalid epoch".to_string(),
+            ))
+        }))
         .and(warp::path::end())
         .and(not_while_syncing_filter.clone())
         .and(warp::body::json())