diff --git a/core/combo/HOST_darwin-x86.mk b/core/combo/HOST_darwin-x86.mk
index 0aa27b1..121f89b 100644
--- a/core/combo/HOST_darwin-x86.mk
+++ b/core/combo/HOST_darwin-x86.mk
@@ -23,6 +23,21 @@
 HOST_GLOBAL_CFLAGS += -m32
 HOST_GLOBAL_LDFLAGS += -m32
 
+# Use the Mac OSX SDK 10.5 if the build host is 10.6
+build_mac_version := $(shell sw_vers -productVersion)
+ifneq ($(filter 10.6.%, $(build_mac_version)),)
+sdk_105_root := /Developer/SDKs/MacOSX10.5.sdk
+ifeq ($(wildcard $(sdk_105_root)),)
+$(warning *****************************************************)
+$(warning * You are building on Mac OSX 10.6.)
+$(warning * Can not find SDK 10.5 at $(sdk_105_root))
+$(warning *****************************************************)
+$(error Stop.)
+endif
+
+HOST_GLOBAL_CFLAGS += -isysroot $(sdk_105_root) -mmacosx-version-min=10.5
+HOST_GLOBAL_LDFLAGS += -isysroot $(sdk_105_root) -mmacosx-version-min=10.5
+endif # build_mac_version is 10.6
 
 HOST_GLOBAL_CFLAGS += -fPIC
 HOST_NO_UNDEFINED_LDFLAGS := -Wl,-undefined,error