diff --git a/system_wrappers/source/cpu_info.cc b/system_wrappers/source/cpu_info.cc
index 6bcdd5f94f..7288c67efd 100644
--- a/system_wrappers/source/cpu_info.cc
+++ b/system_wrappers/source/cpu_info.cc
@@ -24,8 +24,7 @@
 
 namespace internal {
 static int DetectNumberOfCores() {
-  // We fall back on assuming a single core in case of errors.
-  int number_of_cores = 1;
+  int number_of_cores;
 
 #if defined(WEBRTC_WIN)
   SYSTEM_INFO si;
@@ -33,6 +32,10 @@ static int DetectNumberOfCores() {
   number_of_cores = static_cast<int>(si.dwNumberOfProcessors);
 #elif defined(WEBRTC_LINUX) || defined(WEBRTC_ANDROID)
   number_of_cores = static_cast<int>(sysconf(_SC_NPROCESSORS_ONLN));
+  if (number_of_cores < 0) {
+    RTC_LOG(LS_ERROR) << "Failed to get number of cores";
+    number_of_cores = 1;
+  }
 #elif defined(WEBRTC_MAC) || defined(WEBRTC_IOS)
   int name[] = {CTL_HW, HW_AVAILCPU};
   size_t size = sizeof(number_of_cores);
@@ -44,10 +47,12 @@ static int DetectNumberOfCores() {
   number_of_cores = zx_system_get_num_cpus();
 #else
   RTC_LOG(LS_ERROR) << "No function to get number of cores";
+  number_of_cores = 1;
 #endif
 
   RTC_LOG(LS_INFO) << "Available number of cores: " << number_of_cores;
 
+  RTC_CHECK_GT(number_of_cores, 0);
   return number_of_cores;
 }
 }  // namespace internal
@@ -59,9 +64,8 @@ uint32_t CpuInfo::DetectNumberOfCores() {
   // is running in a sandbox, we may only be able to read the value once (before
   // the sandbox is initialized) and not thereafter.
   // For more information see crbug.com/176522.
-  static uint32_t logical_cpus = 0;
-  if (!logical_cpus)
-    logical_cpus = static_cast<uint32_t>(internal::DetectNumberOfCores());
+  static const uint32_t logical_cpus =
+      static_cast<uint32_t>(internal::DetectNumberOfCores());
   return logical_cpus;
 }