diff --git a/build/Android.common.mk b/build/Android.common.mk
index 6135571..188ddb5 100644
--- a/build/Android.common.mk
+++ b/build/Android.common.mk
@@ -110,6 +110,12 @@
 DALVIKVM_FLAGS := -Xcompiler-option --compiler-backend=Optimizing
 endif
 
+#
+# Used to change the default GC. Valid values are CMS, SS, GSS. The default is CMS.
+#
+ART_DEFAULT_GC_TYPE ?= CMS
+ART_DEFAULT_GC_TYPE_CFLAGS := -DART_DEFAULT_GC_TYPE_IS_$(ART_DEFAULT_GC_TYPE)
+
 LLVM_ROOT_PATH := external/llvm
 # Don't fail a dalvik minimal host build.
 -include $(LLVM_ROOT_PATH)/llvm.mk
@@ -237,6 +243,7 @@
 
 ART_HOST_CFLAGS := $(art_cflags) -DANDROID_SMP=1 -DART_BASE_ADDRESS=$(LIBART_IMG_HOST_BASE_ADDRESS)
 ART_HOST_CFLAGS += -DART_DEFAULT_INSTRUCTION_SET_FEATURES=default
+ART_HOST_CFLAGS += $(ART_DEFAULT_GC_TYPE_CFLAGS)
 
 ART_TARGET_CFLAGS := $(art_cflags) -DART_TARGET -DART_BASE_ADDRESS=$(LIBART_IMG_TARGET_BASE_ADDRESS)
 ifeq ($(TARGET_CPU_SMP),true)
@@ -244,6 +251,7 @@
 else
   ART_TARGET_CFLAGS += -DANDROID_SMP=0
 endif
+ART_TARGET_CFLAGS += $(ART_DEFAULT_GC_TYPE_CFLAGS)
 
 # DEX2OAT_TARGET_INSTRUCTION_SET_FEATURES is set in ../build/core/dex_preopt.mk based on
 # the TARGET_CPU_VARIANT
diff --git a/runtime/parsed_options.cc b/runtime/parsed_options.cc
index 1562527..304a0d7 100644
--- a/runtime/parsed_options.cc
+++ b/runtime/parsed_options.cc
@@ -181,8 +181,16 @@
   parallel_gc_threads_ = sysconf(_SC_NPROCESSORS_CONF) - 1;
   // Only the main GC thread, no workers.
   conc_gc_threads_ = 0;
-  // Default is CMS which is Sticky + Partial + Full CMS GC.
+  // The default GC type is set in makefiles.
+#if ART_DEFAULT_GC_TYPE_IS_CMS
   collector_type_ = gc::kCollectorTypeCMS;
+#elif ART_DEFAULT_GC_TYPE_IS_SS
+  collector_type_ = gc::kCollectorTypeSS;
+#elif ART_DEFAULT_GC_TYPE_IS_GSS
+  collector_type_ = gc::kCollectorTypeGSS;
+#else
+#error "ART default GC type must be set"
+#endif
   // If background_collector_type_ is kCollectorTypeNone, it defaults to the collector_type_ after
   // parsing options.
   background_collector_type_ = gc::kCollectorTypeNone;