diff --git a/mozilla/security/coreconf/Darwin.mk b/mozilla/security/coreconf/Darwin.mk
index a78894e42bf..c9d67a7dca5 100644
--- a/mozilla/security/coreconf/Darwin.mk
+++ b/mozilla/security/coreconf/Darwin.mk
@@ -131,4 +131,5 @@ DLL_SUFFIX	= dylib
 PROCESS_MAP_FILE = grep -v ';+' $< | grep -v ';-' | \
                 sed -e 's; DATA ;;' -e 's,;;,,' -e 's,;.*,,' -e 's,^,_,' > $@
 
-G++INCLUDES	= -I/usr/include/g++
+USE_SYSTEM_ZLIB = 1
+ZLIB_LIBS	= -lz
diff --git a/mozilla/security/nss/cmd/modutil/Makefile b/mozilla/security/nss/cmd/modutil/Makefile
index 8bdb8658d64..a0c1ba50f43 100644
--- a/mozilla/security/nss/cmd/modutil/Makefile
+++ b/mozilla/security/nss/cmd/modutil/Makefile
@@ -57,6 +57,12 @@ include $(CORE_DEPTH)/coreconf/config.mk
 #######################################################################
 include ../platlibs.mk
 
+ifdef USE_SYSTEM_ZLIB
+OS_LIBS += $(ZLIB_LIBS)
+else
+EXTRA_LIBS += $(ZLIB_LIBS)
+endif
+
 #######################################################################
 # (5) Execute "global" rules. (OPTIONAL)                              #
 #######################################################################
diff --git a/mozilla/security/nss/cmd/platlibs.mk b/mozilla/security/nss/cmd/platlibs.mk
index d02f66f292b..65969fcb7ed 100644
--- a/mozilla/security/nss/cmd/platlibs.mk
+++ b/mozilla/security/nss/cmd/platlibs.mk
@@ -250,6 +250,4 @@ ifndef USE_SYSTEM_ZLIB
 ZLIB_LIBS = $(DIST)/lib/$(LIB_PREFIX)zlib.$(LIB_SUFFIX)
 endif
 
-JAR_LIBS = $(DIST)/lib/$(LIB_PREFIX)jar.$(LIB_SUFFIX) \
-	$(ZLIB_LIBS) \
-	$(NULL)
+JAR_LIBS = $(DIST)/lib/$(LIB_PREFIX)jar.$(LIB_SUFFIX)
diff --git a/mozilla/security/nss/cmd/signtool/Makefile b/mozilla/security/nss/cmd/signtool/Makefile
index cd06aaa4fd8..ed6c9fe2472 100644
--- a/mozilla/security/nss/cmd/signtool/Makefile
+++ b/mozilla/security/nss/cmd/signtool/Makefile
@@ -58,6 +58,12 @@ include $(CORE_DEPTH)/coreconf/config.mk
 
 include ../platlibs.mk
 
+ifdef USE_SYSTEM_ZLIB
+OS_LIBS += $(ZLIB_LIBS)
+else
+EXTRA_LIBS += $(ZLIB_LIBS)
+endif
+
 #######################################################################
 # (5) Execute "global" rules. (OPTIONAL)                              #
 #######################################################################