Index: MultiSource/Benchmarks/DOE-ProxyApps-C++/CLAMR/clamr_cpuonly.cpp
===================================================================
--- MultiSource/Benchmarks/DOE-ProxyApps-C++/CLAMR/clamr_cpuonly.cpp
+++ MultiSource/Benchmarks/DOE-ProxyApps-C++/CLAMR/clamr_cpuonly.cpp
@@ -499,7 +499,7 @@
 
    int error_status = STATUS_OK;
 
-   if (isnan(H_sum)) {
+   if (::isnan(H_sum)) {
       printf("Got a NAN on cycle %d\n",ncycle);
       error_status = STATUS_NAN;
    }