Index: MultiSource/Benchmarks/DOE-ProxyApps-C++/miniFE/CMakeLists.txt
===================================================================
--- MultiSource/Benchmarks/DOE-ProxyApps-C++/miniFE/CMakeLists.txt
+++ MultiSource/Benchmarks/DOE-ProxyApps-C++/miniFE/CMakeLists.txt
@@ -1,4 +1,9 @@
 list(APPEND CXXFLAGS -I. -DMINIFE_SCALAR=double  -DMINIFE_LOCAL_ORDINAL=int -DMINIFE_GLOBAL_ORDINAL=int -DMINIFE_CSR_MATRIX -DREDSTORM) # -DREDSTORM for mkdir
+# Use X/OPEN compatibility flag on AIX to avoid problems with some
+# versions of the system headers.
+if(CMAKE_SYSTEM_NAME STREQUAL "AIX")
+  set_source_files_properties(main.cpp PROPERTIES COMPILE_OPTIONS -D_XOPEN_SOURCE=700)
+endif()
 list(APPEND LDFLAGS -lm)
 set(RUN_OPTIONS -nx 64 -ny 64 -nz 64)
 llvm_multisource(miniFE)