diff --git a/web3_proxy/src/app/mod.rs b/web3_proxy/src/app/mod.rs
index 5f977fed..75610ca2 100644
--- a/web3_proxy/src/app/mod.rs
+++ b/web3_proxy/src/app/mod.rs
@@ -669,14 +669,12 @@ impl Web3ProxyApp {
             ));
         }
 
-        // keep 1GB of blocks in the cache
-        // responses can be very different in sizes, so this definitely needs a weigher
-        // TODO: max_capacity from config
+        // responses can be very different in sizes, so this is a cache with a max capacity and a weigher
         // TODO: don't allow any response to be bigger than X% of the cache
         let response_cache = Cache::builder()
-            .max_capacity(1024 * 1024 * 1024)
+            .max_capacity(top_config.app.response_cache_max_bytes)
             .weigher(|k: &ResponseCacheKey, v| {
-                // TODO: is this good?
+                // TODO: is this good enough?
                 if let Ok(v) = serde_json::to_string(v) {
                     let weight = k.weight() + v.len();
 
diff --git a/web3_proxy/src/config.rs b/web3_proxy/src/config.rs
index 567c14d9..942632e7 100644
--- a/web3_proxy/src/config.rs
+++ b/web3_proxy/src/config.rs
@@ -138,7 +138,7 @@ pub struct AppConfig {
 
     /// RPC responses are cached locally
     #[serde(default = "default_response_cache_max_bytes")]
-    pub response_cache_max_bytes: usize,
+    pub response_cache_max_bytes: u64,
 
     /// the stats page url for an anonymous user.
     pub redirect_public_url: Option<String>,
@@ -190,10 +190,10 @@ fn default_login_rate_limit_per_period() -> u64 {
     10
 }
 
-fn default_response_cache_max_bytes() -> usize {
+fn default_response_cache_max_bytes() -> u64 {
     // TODO: default to some percentage of the system?
     // 100 megabytes
-    10_usize.pow(8)
+    10u64.pow(8)
 }
 
 /// Configuration for a backend web3 RPC server