diff --git a/External/SPEC/CFP2017rate/527.cam4_r/CMakeLists.txt b/External/SPEC/CFP2017rate/527.cam4_r/CMakeLists.txt
--- a/External/SPEC/CFP2017rate/527.cam4_r/CMakeLists.txt
+++ b/External/SPEC/CFP2017rate/527.cam4_r/CMakeLists.txt
@@ -571,8 +571,8 @@
   zenith.F90
 )
 
-check_fortran_compiler_flag("-fallow-argument-mismatch" ALLOW_MISMATCH)
-if (ALLOW_MISMATCH)
+check_fortran_compiler_flag("-fallow-argument-mismatch" SUPPORTS_FALLOW_ARGUMENT_MISMATCH)
+if (SUPPORTS_FALLOW_ARGUMENT_MISMATCH)
   target_compile_options(${PROG} PRIVATE $<$<COMPILE_LANGUAGE:Fortran>:-fallow-argument-mismatch>)
 endif ()