diff --git a/build_files/scons/config/win64-vc-config.py b/build_files/scons/config/win64-vc-config.py
index 3a376be6024..9e36be42329 100644
--- a/build_files/scons/config/win64-vc-config.py
+++ b/build_files/scons/config/win64-vc-config.py
@@ -166,7 +166,8 @@ BF_CYCLES_CUDA_BINARIES_ARCH = ['sm_13', 'sm_20', 'sm_21']
 
 #Ray trace optimization
 WITH_BF_RAYOPTIMIZATION = True
-BF_RAYOPTIMIZATION_SSE_FLAGS = ['/arch:SSE','/arch:SSE2']
+# No need to manually specify SSE/SSE2 on x64 systems.
+BF_RAYOPTIMIZATION_SSE_FLAGS = ['']
 
 WITH_BF_STATICOPENGL = False
 BF_OPENGL_INC = '${BF_OPENGL}/include'
diff --git a/intern/cycles/SConscript b/intern/cycles/SConscript
index 34c6e8df2fd..03880bddd8a 100644
--- a/intern/cycles/SConscript
+++ b/intern/cycles/SConscript
@@ -46,8 +46,10 @@ if env['OURPLATFORM'] in ('win32-vc', 'win32-mingw', 'linuxcross', 'win64-vc', '
 if env['WITH_BF_RAYOPTIMIZATION']:
     optim_cxxflags = []
 
-    if env['OURPLATFORM'] in ('win32-vc', 'win64-vc'):
+    if env['OURPLATFORM'] == 'win32-vc':
         optim_cxxflags.append('/arch:SSE2 -D_CRT_SECURE_NO_WARNINGS /fp:fast /EHsc'.split())
+    elif env['OURPLATFORM'] == 'win64-vc':
+        optim_cxxflags.append('-D_CRT_SECURE_NO_WARNINGS /fp:fast /EHsc'.split())
     else:
         optim_cxxflags.append('-ffast-math -msse -msse2 -msse3 -mfpmath=sse'.split())