diff --git a/Android.mk b/Android.mk
index 46deaaf2..870ffe43 100644
--- a/Android.mk
+++ b/Android.mk
@@ -55,6 +55,10 @@ ifneq ($(BOARD_VOLD_MAX_PARTITIONS),)
 LOCAL_CFLAGS += -DVOLD_MAX_PARTITIONS=$(BOARD_VOLD_MAX_PARTITIONS)
 endif
 
+ifeq ($(BOARD_VOLD_EMMC_SHARES_DEV_MAJOR), true)
+LOCAL_CFLAGS += -DVOLD_EMMC_SHARES_DEV_MAJOR
+endif
+
 ifneq ($(TARGET_USE_CUSTOM_LUN_FILE_PATH),)
 LOCAL_CFLAGS += -DCUSTOM_LUN_FILE=\"$(TARGET_USE_CUSTOM_LUN_FILE_PATH)\"
 endif
diff --git a/Volume.cpp b/Volume.cpp
index c4d26494..a42c1990 100644
--- a/Volume.cpp
+++ b/Volume.cpp
@@ -233,6 +233,15 @@ int Volume::formatVol() {
     sprintf(devicePath, "/dev/block/vold/%d:%d",
             MAJOR(partNode), MINOR(partNode));
 
+#ifdef VOLD_EMMC_SHARES_DEV_MAJOR
+    // If emmc and sdcard share dev major number, vold may pick
+    // incorrectly based on partition nodes alone, formatting
+    // the wrong device. Use device nodes instead.
+    dev_t deviceNodes;
+    getDeviceNodes((dev_t *) &deviceNodes, 1);
+    sprintf(devicePath, "/dev/block/vold/%d:%d", MAJOR(deviceNodes), MINOR(deviceNodes));
+#endif
+
     if (mDebug) {
         SLOGI("Formatting volume %s (%s)", getLabel(), devicePath);
     }