diff --git a/health/health.go b/health/health.go
index 62e4043499..794d243e04 100644
--- a/health/health.go
+++ b/health/health.go
@@ -29,10 +29,10 @@ var (
 )
 
 type requestBody struct {
-	Synced           *bool   `json:"synced"`
-	MinPeerCount     *uint   `json:"min_peer_count"`
-	CheckBlock       *uint64 `json:"check_block"`
-	MaxSecondsBehind *int    `json:"max_seconds_behind"`
+	Synced           *bool    `json:"synced"`
+	MinPeerCount     *uint    `json:"min_peer_count"`
+	CheckBlock       *big.Int `json:"check_block"`
+	MaxSecondsBehind *int     `json:"max_seconds_behind"`
 }
 
 // processFromHeaders handles requests when 'X-GETH-HEALTHCHECK' header labels are present.
@@ -105,7 +105,7 @@ func processFromBody(ec ethClient, w http.ResponseWriter, r *http.Request) {
 		}
 
 		if body.CheckBlock != nil {
-			errCheckBlock = checkBlockNumber(ec, big.NewInt(int64(*body.CheckBlock)))
+			errCheckBlock = checkBlockNumber(ec, body.CheckBlock)
 		}
 
 		if body.MaxSecondsBehind != nil {
diff --git a/health/health_test.go b/health/health_test.go
index 86c5ee07b4..f1422d789c 100644
--- a/health/health_test.go
+++ b/health/health_test.go
@@ -585,7 +585,7 @@ func TestProcessFromBody(t *testing.T) {
 			clientSyncingError:  nil,
 			expectedStatusCode:  http.StatusInternalServerError,
 			expectedBody: map[string]string{
-				query:            "ERROR: json: cannot unmarshal string into Go struct field requestBody.check_block of type uint64",
+				query:            "ERROR: math/big: cannot unmarshal \"\\\"ABC\\\"\" into a *big.Int",
 				synced:           "DISABLED",
 				minPeerCount:     "DISABLED",
 				checkBlock:       "DISABLED",