diff --git a/Makefile b/Makefile
index 299970c67..8621a8b3f 100644
--- a/Makefile
+++ b/Makefile
@@ -35,7 +35,11 @@ export NO_LAPACK
 export C_LAPACK
 endif
 
+ifeq ($(F_COMPILER),CRAY)
+LAPACK_NOOPT := $(filter-out -O0 -O1 -O2 -O3 -Ofast -Og -Os,$(LAPACK_FFLAGS))
+else
 LAPACK_NOOPT := $(filter-out -O0 -O1 -O2 -O3 -Ofast -O -Og -Os,$(LAPACK_FFLAGS))
+endif
 
 SUBDIRS_ALL = $(SUBDIRS) test ctest utest exports benchmark ../laswp ../bench cpp_thread_test
 
diff --git a/Makefile.system b/Makefile.system
index 77c36c870..868cca4f9 100644
--- a/Makefile.system
+++ b/Makefile.system
@@ -1642,11 +1642,11 @@ endif
 
 ifeq ($(F_COMPILER),NAG)
 LAPACK_FFLAGS := $(filter-out -msse3 -mssse3 -msse4.1 -mavx -mavx2 -mskylake-avx512 ,$(FFLAGS))
-FFLAGS := $(filter-out -msse3 -mssse3 -msse4.1 -mavx -mavx2 -mskylake-avx512 ,$(FFLAGS))
+override FFLAGS := $(filter-out -msse3 -mssse3 -msse4.1 -mavx -mavx2 -mskylake-avx512 ,$(FFLAGS))
 endif
 ifeq ($(F_COMPILER),CRAY)
 LAPACK_FFLAGS := $(filter-out -msse3 -mssse3 -msse4.1 -mavx -mavx2 -mskylake-avx512 ,$(FFLAGS))
-FFLAGS := $(filter-out -msse3 -mssse3 -msse4.1 -mavx -mavx2 -mskylake-avx512 ,$(FFLAGS))
+override FFLAGS := $(filter-out -msse3 -mssse3 -msse4.1 -mavx -mavx2 -mskylake-avx512 ,$(FFLAGS))
 endif
 
 LAPACK_CFLAGS = $(CFLAGS)