diff --git a/python/mozbuild/mozbuild/telemetry.py b/python/mozbuild/mozbuild/telemetry.py
index 75b6ed0d9a52f..be6b6dbaf687a 100644
--- a/python/mozbuild/mozbuild/telemetry.py
+++ b/python/mozbuild/mozbuild/telemetry.py
@@ -177,7 +177,9 @@ def get_system_info():
         import psutil
 
         info['logical_cores'] = psutil.cpu_count()
-        info['physical_cores'] = psutil.cpu_count(logical=False)
+        physical_cores = psutil.cpu_count(logical=False)
+        if physical_cores is not None:
+            info['physical_cores'] = physical_cores
         # `total` on Linux is gathered from /proc/meminfo's `MemTotal`, which is the total
         # amount of physical memory minus some kernel usage, so round up to the nearest GB
         # to get a sensible answer.