diff --git a/examples/volume_rendering/Makefile b/examples/volume_rendering/Makefile
index 0f3f83b2..fa8ff753 100644
--- a/examples/volume_rendering/Makefile
+++ b/examples/volume_rendering/Makefile
@@ -8,7 +8,7 @@ TASK_OBJ=$(addprefix objs/, $(subst ../,, $(TASK_CXX:.cpp=.o)))
 CXX=g++
 CXXFLAGS=-Iobjs/ -O3 -Wall -m64
 ISPC=ispc
-ISPCFLAGS=-O2 --target=sse2,sse4-x2 --arch=x86-64 --opt=32-bit-addressing
+ISPCFLAGS=-O2 --target=sse2,sse4-x2 --arch=x86-64
 
 OBJS=objs/volume.o objs/volume_serial.o $(TASK_OBJ) objs/volume_ispc.o \
 	objs/volume_ispc_sse2.o objs/volume_ispc_sse4.o
diff --git a/examples/volume_rendering/volume.vcxproj b/examples/volume_rendering/volume.vcxproj
index 423c26fc..04ae8335 100644
--- a/examples/volume_rendering/volume.vcxproj
+++ b/examples/volume_rendering/volume.vcxproj
@@ -158,13 +158,13 @@
       <FileType>Document</FileType>
       <Command Condition="'$(Configuration)|$(Platform)'=='Debug|Win32'">ispc -O2 %(Filename).ispc -o $(TargetDir)%(Filename).obj -h $(TargetDir)%(Filename)_ispc.h --arch=x86 --target=sse2,sse4-x2
 </Command>
-      <Command Condition="'$(Configuration)|$(Platform)'=='Debug|x64'">ispc -O2 %(Filename).ispc -o $(TargetDir)%(Filename).obj -h $(TargetDir)%(Filename)_ispc.h --target=sse2,sse4-x2 --opt=32-bit-addressing
+      <Command Condition="'$(Configuration)|$(Platform)'=='Debug|x64'">ispc -O2 %(Filename).ispc -o $(TargetDir)%(Filename).obj -h $(TargetDir)%(Filename)_ispc.h --target=sse2,sse4-x2
 </Command>
       <Outputs Condition="'$(Configuration)|$(Platform)'=='Debug|Win32'">$(TargetDir)%(Filename).obj;$(TargetDir)%(Filename)_sse2.obj;$(TargetDir)%(Filename)_sse4.obj;$(TargetDir)%(Filename)_ispc.h</Outputs>
       <Outputs Condition="'$(Configuration)|$(Platform)'=='Debug|x64'">$(TargetDir)%(Filename).obj;$(TargetDir)%(Filename)_sse2.obj;$(TargetDir)%(Filename)_sse4.obj;$(TargetDir)%(Filename)_ispc.h</Outputs>
       <Command Condition="'$(Configuration)|$(Platform)'=='Release|Win32'">ispc -O2 %(Filename).ispc -o $(TargetDir)%(Filename).obj -h $(TargetDir)%(Filename)_ispc.h --arch=x86 --target=sse2,sse4-x2
 </Command>
-      <Command Condition="'$(Configuration)|$(Platform)'=='Release|x64'">ispc -O2 %(Filename).ispc -o $(TargetDir)%(Filename).obj -h $(TargetDir)%(Filename)_ispc.h --target=sse2,sse4-x2 --opt=32-bit-addressing
+      <Command Condition="'$(Configuration)|$(Platform)'=='Release|x64'">ispc -O2 %(Filename).ispc -o $(TargetDir)%(Filename).obj -h $(TargetDir)%(Filename)_ispc.h --target=sse2,sse4-x2
 </Command>
       <Outputs Condition="'$(Configuration)|$(Platform)'=='Release|Win32'">$(TargetDir)%(Filename).obj;$(TargetDir)%(Filename)_sse2.obj;$(TargetDir)%(Filename)_sse4.obj;$(TargetDir)%(Filename)_ispc.h</Outputs>
       <Outputs Condition="'$(Configuration)|$(Platform)'=='Release|x64'">$(TargetDir)%(Filename).obj;$(TargetDir)%(Filename)_sse2.obj;$(TargetDir)%(Filename)_sse4.obj;$(TargetDir)%(Filename)_ispc.h</Outputs>