diff --git a/SetFlags.cmake b/SetFlags.cmake
index 6e86ac0aa..a5bd3a0a2 100644
--- a/SetFlags.cmake
+++ b/SetFlags.cmake
@@ -1,4 +1,3 @@
-
 macro (add_flags_lnk FLAGS)
 	set(CMAKE_EXE_LINKER_FLAGS            "${CMAKE_EXE_LINKER_FLAGS}            ${FLAGS}")
 	set(CMAKE_EXE_LINKER_FLAGS_DEBUG      "${CMAKE_EXE_LINKER_FLAGS_DEBUG}      ${FLAGS}")
@@ -49,9 +48,6 @@ macro(set_flags)
 		else()
 			add_flags_cxx("-pthread")
 		endif()
-		
-		#we support non-IEEE 754 fpus so can make no guarentees about error
-		add_flags_cxx("-ffast-math")
 
 	else()
 		# Let gcc / clang know that we're compiling a multi-threaded app:
@@ -65,8 +61,6 @@ macro(set_flags)
 		# We use a signed char (fixes #640 on RasPi)
 		add_flags_cxx("-fsigned-char")
 		
-		#we support non-IEEE 754 fpus so can make no guarentees about error
-		add_flags_cxx("-ffast-math")
 	endif()
 
 
@@ -189,6 +183,9 @@ macro(set_exe_flags)
 		string(REPLACE "-w" "" CMAKE_CXX_FLAGS_DEBUG   "${CMAKE_CXX_FLAGS_DEBUG}")
 		string(REPLACE "-w" "" CMAKE_C_FLAGS_DEBUG     "${CMAKE_C_FLAGS_DEBUG}")
 		add_flags_cxx("-Wall -Wextra")
+		
+		#we support non-IEEE 754 fpus so can make no guarentees about error
+		add_flags_cxx("-ffast-math")
 	endif()
 
 endmacro()