diff --git a/include/aws/s3/s3_client.h b/include/aws/s3/s3_client.h
index 4a161ef62..1cd6d9c8b 100644
--- a/include/aws/s3/s3_client.h
+++ b/include/aws/s3/s3_client.h
@@ -421,8 +421,8 @@ struct aws_s3_client_config {
     /* Throughput target in gigabits per second (Gbps) that we are trying to reach. */
     double throughput_target_gbps;
 
-    /* How much memory can we use. */
-    size_t memory_limit_in_bytes;
+    /* How much memory can we use. This will be capped to SIZE_MAX */
+    uint64_t memory_limit_in_bytes;
 
     /* Retry strategy to use. If NULL, a default retry strategy will be used. */
     struct aws_retry_strategy *retry_strategy;
diff --git a/source/s3_client.c b/source/s3_client.c
index 6405a5412..d4eafcc22 100644
--- a/source/s3_client.c
+++ b/source/s3_client.c
@@ -342,7 +342,12 @@ struct aws_s3_client *aws_s3_client_new(
         }
 #endif
     } else {
-        mem_limit = client_config->memory_limit_in_bytes;
+        // cap memory limit to SIZE_MAX
+        if (client_config->memory_limit_in_bytes > SIZE_MAX) {
+            mem_limit = SIZE_MAX;
+        } else {
+            mem_limit = (size_t)client_config->memory_limit_in_bytes;
+        }
     }
 
     size_t part_size = s_default_part_size;