diff --git a/Withings.NET/Client/Authenticator.cs b/Withings.NET/Client/Authenticator.cs
index 2358d09..b47a990 100644
--- a/Withings.NET/Client/Authenticator.cs
+++ b/Withings.NET/Client/Authenticator.cs
@@ -60,8 +60,13 @@ public async Task<OAuthToken> GetAccessToken(string code)
             var httpResponse = await _httpClient.PostAsync(TokenUrl, content).ConfigureAwait(false);
             httpResponse.EnsureSuccessStatusCode();
 
-            var json = await httpResponse.Content.ReadAsStringAsync().ConfigureAwait(false);
-            var response = JsonSerializer.Deserialize<WithingsResponse<OAuthToken>>(json);
+            using var stream = await httpResponse.Content.ReadAsStreamAsync().ConfigureAwait(false);
+            var response = await JsonSerializer.DeserializeAsync<WithingsResponse<OAuthToken>>(stream).ConfigureAwait(false);
+
+            if (response == null)
+            {
+                 throw new WithingsApiException(-1, "Empty response from Withings API");
+            }
 
             if (response.Status != 0)
             {
@@ -85,8 +90,13 @@ public async Task<OAuthToken> RefreshAccessToken(string refreshToken)
             var httpResponse = await _httpClient.PostAsync(TokenUrl, content).ConfigureAwait(false);
             httpResponse.EnsureSuccessStatusCode();
 
-            var json = await httpResponse.Content.ReadAsStringAsync().ConfigureAwait(false);
-            var response = JsonSerializer.Deserialize<WithingsResponse<OAuthToken>>(json);
+            using var stream = await httpResponse.Content.ReadAsStreamAsync().ConfigureAwait(false);
+            var response = await JsonSerializer.DeserializeAsync<WithingsResponse<OAuthToken>>(stream).ConfigureAwait(false);
+
+            if (response == null)
+            {
+                 throw new WithingsApiException(-1, "Empty response from Withings API");
+            }
 
             if (response.Status != 0)
             {
diff --git a/Withings.NET/Client/WithingsClient.cs b/Withings.NET/Client/WithingsClient.cs
index 4525996..b7a7623 100644
--- a/Withings.NET/Client/WithingsClient.cs
+++ b/Withings.NET/Client/WithingsClient.cs
@@ -31,11 +31,11 @@ private async Task<ExpandoObject> GetAsync(string url, string accessToken)
             var request = new HttpRequestMessage(HttpMethod.Get, url);
             request.Headers.Authorization = new AuthenticationHeaderValue("Bearer", accessToken);
 
-            var response = await _httpClient.SendAsync(request).ConfigureAwait(false);
+            using var response = await _httpClient.SendAsync(request, HttpCompletionOption.ResponseHeadersRead).ConfigureAwait(false);
             response.EnsureSuccessStatusCode();
 
-            var json = await response.Content.ReadAsStringAsync().ConfigureAwait(false);
-            return JsonSerializer.Deserialize<ExpandoObject>(json, _jsonOptions);
+            using var stream = await response.Content.ReadAsStreamAsync().ConfigureAwait(false);
+            return await JsonSerializer.DeserializeAsync<ExpandoObject>(stream, _jsonOptions).ConfigureAwait(false);
         }
 
         private static string BuildUrl(string path, params (string key, string value)[] queryParams)