diff --git a/src/utils_qualtest.py b/src/utils_qualtest.py
index 6920272..4f854cc 100644
--- a/src/utils_qualtest.py
+++ b/src/utils_qualtest.py
@@ -78,7 +78,7 @@ class QualtestBackend:
             r = requests.post(url=url, json=report, timeout=utils.NETWORK_TIMEOUT)
             utils.log_verbose(f"Upload report finished. Response (probe ID): {r.content}")
             if r.status_code != 200:
-                if r.status_code == 500 and 'Duplicate entry' in r.content().decode():
+                if r.status_code == 500 and 'Duplicate entry' in r.content.decode():
                     # Suppose it success
                     result = (report['id'], True)
                 else: