diff --git a/cmake/Compiler-Intel.cmake b/cmake/Compiler-Intel.cmake
index 4125aa8ef..b8aa2609e 100644
--- a/cmake/Compiler-Intel.cmake
+++ b/cmake/Compiler-Intel.cmake
@@ -29,8 +29,8 @@ set (LINKER_FLAGS   "${LINKER_FLAGS} -shared-intel")
 set (COMPILE_FLAGS "${COMPILE_FLAGS} -fpp")
 # preprocessor
 
-set (COMPILE_FLAGS "${COMPILE_FLAGS} -ftz")
-# flush underflow to zero, automatically set if -O[1,2,3]
+set (COMPILE_FLAGS "${COMPILE_FLAGS} -no-ftz")
+# disable flush underflow to zero, will be set if -O[1,2,3]
 
 set (COMPILE_FLAGS "${COMPILE_FLAGS} -diag-disable")
 # disables warnings ...
diff --git a/cmake/Compiler-IntelLLVM.cmake b/cmake/Compiler-IntelLLVM.cmake
index bd0f07ee8..57a14a322 100644
--- a/cmake/Compiler-IntelLLVM.cmake
+++ b/cmake/Compiler-IntelLLVM.cmake
@@ -29,8 +29,8 @@ set (LINKER_FLAGS   "${LINKER_FLAGS} -shared-intel")
 set (COMPILE_FLAGS "${COMPILE_FLAGS} -fpp")
 # preprocessor
 
-set (COMPILE_FLAGS "${COMPILE_FLAGS} -ftz")
-# flush underflow to zero, automatically set if -O[1,2,3]
+set (COMPILE_FLAGS "${COMPILE_FLAGS} -no-ftz")
+# disable flush underflow to zero, will be set if -O[1,2,3]
 
 set (COMPILE_FLAGS "${COMPILE_FLAGS} -diag-disable")
 # disables warnings ...