diff --git a/etc/c/zlib/win64.mak b/etc/c/zlib/win64.mak
index 1d327a2ab..1edfd0e65 100644
--- a/etc/c/zlib/win64.mak
+++ b/etc/c/zlib/win64.mak
@@ -1,12 +1,12 @@
 # Makefile for zlib64
 
-VCDIR="\Program Files (x86)\Microsoft Visual Studio 10.0\VC"
+VCDIR=\Program Files (x86)\Microsoft Visual Studio 10.0\VC
 
-CC=$(VCDIR)\bin\amd64\cl
-LD=$(VCDIR)\bin\amd64\link
-LIB=$(VCDIR)\bin\amd64\lib
+CC="$(VCDIR)\bin\amd64\cl"
+LD="$(VCDIR)\bin\amd64\link"
+LIB="$(VCDIR)\bin\amd64\lib"
 
-CFLAGS=/O2 /nologo /I$(VCDIR)\INCLUDE
+CFLAGS=/O2 /nologo /I"$(VCDIR)\INCLUDE"
 LIBFLAGS=/nologo
 LDFLAGS=/nologo
 O=.obj
diff --git a/win64.mak b/win64.mak
index a386d86b6..2da009845 100644
--- a/win64.mak
+++ b/win64.mak
@@ -27,13 +27,13 @@ CP=cp
 DIR=\dmd2
 
 ## Visual C directories
-VCDIR="\Program Files (x86)\Microsoft Visual Studio 10.0\VC"
-SDKDIR="\Program Files (x86)\Microsoft SDKs\Windows\v7.0A"
+VCDIR=\Program Files (x86)\Microsoft Visual Studio 10.0\VC
+SDKDIR=\Program Files (x86)\Microsoft SDKs\Windows\v7.0A
 
 ## Flags for VC compiler
 
-#CFLAGS=/Zi /nologo /I$(VCDIR)\INCLUDE /I$(SDKDIR)\Include
-CFLAGS=/O2 /nologo /I$(VCDIR)\INCLUDE /I$(SDKDIR)\Include
+#CFLAGS=/Zi /nologo /I"$(VCDIR)\INCLUDE" /I"$(SDKDIR)\Include"
+CFLAGS=/O2 /nologo /I"$(VCDIR)\INCLUDE" /I"$(SDKDIR)\Include"
 
 ## Flags for dmd D compiler
 
@@ -47,9 +47,9 @@ UDFLAGS=-g -m$(MODEL) -O -w -d -property
 
 ## C compiler, linker, librarian
 
-CC=$(VCDIR)\bin\amd64\cl
-LD=$(VCDIR)\bin\amd64\link
-AR=$(VCDIR)\bin\amd64\lib
+CC="$(VCDIR)\bin\amd64\cl"
+LD="$(VCDIR)\bin\amd64\link"
+AR="$(VCDIR)\bin\amd64\lib"
 MAKE=make
 
 ## D compiler
@@ -455,7 +455,7 @@ html : $(DOCS)
 
 $(ZLIB): $(SRC_ZLIB)
 	cd etc\c\zlib
-	$(MAKE) -f win$(MODEL).mak zlib$(MODEL).lib CC=$(CC) LIB=$(AR)
+	$(MAKE) -f win$(MODEL).mak zlib$(MODEL).lib CC=$(CC) LIB=$(AR) VCDIR="$(VCDIR)"
 	cd ..\..\..
 
 ################## DOCS ####################################