diff --git a/Makefile.in b/Makefile.in
index d03c8f9907b2..4abf8d6b851b 100644
--- a/Makefile.in
+++ b/Makefile.in
@@ -472,13 +472,13 @@ endif
 
 # Map mozilla targets to standard automake target
 clobber realclean clobber_all::
-ifndef MOZ_SYSTEM_CAIRO
+ifdef MOZ_TREE_CAIRO
 	$(MAKE) -C gfx/cairo/libpixman clean
 	$(MAKE) -C gfx/cairo/cairo clean
 endif
 
 clean distclean::
-ifndef MOZ_SYSTEM_CAIRO
+ifdef MOZ_TREE_CAIRO
 	$(MAKE) -C gfx/cairo/libpixman $@
 	$(MAKE) -C gfx/cairo/cairo $@
 endif
@@ -533,7 +533,7 @@ ifdef MOZ_LDAP_XPCOM
 endif
 
 cairo:
-ifndef MOZ_SYSTEM_CAIRO
+ifdef MOZ_TREE_CAIRO
 	$(MAKE) -C gfx/cairo/libpixman install
 	$(MAKE) -C gfx/cairo/cairo install
 ifneq ($(OS_ARCH),Darwin)
diff --git a/config/autoconf.mk.in b/config/autoconf.mk.in
index 695d335bff7a..0b1c3aaee539 100644
--- a/config/autoconf.mk.in
+++ b/config/autoconf.mk.in
@@ -170,7 +170,7 @@ NECKO_COOKIES = @NECKO_COOKIES@
 MOZ_NATIVE_ZLIB	= @SYSTEM_ZLIB@
 MOZ_NATIVE_JPEG	= @SYSTEM_JPEG@
 MOZ_NATIVE_PNG	= @SYSTEM_PNG@
-MOZ_SYSTEM_CAIRO = @MOZ_SYSTEM_CAIRO@
+MOZ_TREE_CAIRO = @MOZ_TREE_CAIRO@
 
 MOZ_UPDATE_XTERM = @MOZ_UPDATE_XTERM@
 MOZ_MATHML = @MOZ_MATHML@
diff --git a/configure.in b/configure.in
index 16251305a03f..ab4dc5a432e0 100644
--- a/configure.in
+++ b/configure.in
@@ -5658,19 +5658,20 @@ if test -z "$MACOSX"; then
 fi;
 
 if test "$MOZ_SVG_RENDERER_CAIRO" -o "$MOZ_ENABLE_CAIRO" ; then
+   MOZ_TREE_CAIRO=1
    MOZ_ARG_ENABLE_BOOL(system-cairo,
    [ --enable-system-cairo Use system cairo (located with pkgconfig)],
-   MOZ_SYSTEM_CAIRO=1,
-   MOZ_SYSTEM_CAIRO= )
+   MOZ_TREE_CAIRO=,
+   MOZ_TREE_CAIRO=1 )
 
-   if test "$MOZ_SYSTEM_CAIRO"; then
+   if test -z "$MOZ_TREE_CAIRO"; then
       PKG_CHECK_MODULES(CAIRO, cairo >= $CAIRO_VERSION)
       MOZ_CAIRO_CFLAGS=$CAIRO_CFLAGS
       MOZ_CAIRO_LIBS=$CAIRO_LIBS
    fi
 fi
 
-AC_SUBST(MOZ_SYSTEM_CAIRO)
+AC_SUBST(MOZ_TREE_CAIRO)
 AC_SUBST(MOZ_CAIRO_CFLAGS)
 AC_SUBST(MOZ_CAIRO_LIBS)
 
@@ -6426,32 +6427,29 @@ if test "$MOZ_LDAP_XPCOM"; then
     ac_configure_args="$_SUBDIR_CONFIG_ARGS"
 fi
 
-if test "$MOZ_SVG_RENDERER_CAIRO" -o "$MOZ_ENABLE_CAIRO" ; then
-    if test -z "$MOZ_SYSTEM_CAIRO"; then
-        # these subdirs may not yet have been created in the build tree.
-        # don't use the "-p" switch to mkdir, since not all platforms have it
-        #
-        if test ! -d "gfx/cairo"; then
-            mkdir "gfx/cairo"
-        fi
-        if test ! -d "gfx/cairo/libpixman"; then
-            mkdir "gfx/cairo/libpixman"
-        fi
-        if test ! -d "gfx/cairo/cairo"; then
-            mkdir "gfx/cairo/cairo"
-        fi
-
-        ac_configure_args="$_SUBDIR_CONFIG_ARGS --prefix=$MOZ_BUILD_ROOT/dist --includedir=$MOZ_BUILD_ROOT/dist/include/cairo"
-        AC_OUTPUT_SUBDIRS(gfx/cairo/libpixman)
-
-        export PKG_CONFIG_PATH=$MOZ_BUILD_ROOT/gfx/cairo/libpixman
-        ac_configure_args="$_SUBDIR_CONFIG_ARGS --prefix=$MOZ_BUILD_ROOT/dist --disable-ps --disable-pdf --disable-png --disable-glitz --disable-xcb"
-
-        if test -n "$MACOSX"; then
-            ac_configure_args="$ac_configure_args --disable-freetype --disable-xlib"
-        fi
-
-        AC_OUTPUT_SUBDIRS(gfx/cairo/cairo)
-        ac_configure_args="$_SUBDIR_CONFIG_ARGS"
+if test "$MOZ_TREE_CAIRO"; then
+    # these subdirs may not yet have been created in the build tree.
+    # don't use the "-p" switch to mkdir, since not all platforms have it
+    #
+    if test ! -d "gfx/cairo"; then
+        mkdir "gfx/cairo"
     fi
+    if test ! -d "gfx/cairo/libpixman"; then
+        mkdir "gfx/cairo/libpixman"
+    fi
+    if test ! -d "gfx/cairo/cairo"; then
+        mkdir "gfx/cairo/cairo"
+    fi
+
+    ac_configure_args="$_SUBDIR_CONFIG_ARGS --prefix=$MOZ_BUILD_ROOT/dist --includedir=$MOZ_BUILD_ROOT/dist/include/cairo"
+    AC_OUTPUT_SUBDIRS(gfx/cairo/libpixman)
+
+    export PKG_CONFIG_PATH=$MOZ_BUILD_ROOT/gfx/cairo/libpixman
+    ac_configure_args="$_SUBDIR_CONFIG_ARGS --prefix=$MOZ_BUILD_ROOT/dist --disable-ps --disable-pdf --disable-png --disable-glitz --disable-xcb"
+    if test -n "$MACOSX"; then
+        ac_configure_args="$ac_configure_args --disable-freetype --disable-xlib"
+    fi
+
+    AC_OUTPUT_SUBDIRS(gfx/cairo/cairo)
+    ac_configure_args="$_SUBDIR_CONFIG_ARGS"
 fi