diff --git a/classes/image_types_phosphor.bbclass b/classes/image_types_phosphor.bbclass
new file mode 100644
index 0000000..eef1b1c
--- /dev/null
+++ b/classes/image_types_phosphor.bbclass
@@ -0,0 +1,16 @@
+# Base image class extension, inlined into every image.
+
+def build_uboot(d):
+    fstypes = d.getVar('IMAGE_FSTYPES', True).split()
+    if any([x.endswith('u-boot') for x in fstypes]):
+        return 'image_types_uboot'
+    return ''
+
+
+# Inherit u-boot classes if legacy uboot images are in use.
+IMAGE_TYPE_uboot = '${@build_uboot(d)}'
+inherit ${IMAGE_TYPE_uboot}
+
+# Inherit the overlay class if overlay is in use.
+IMAGE_TYPE_overlay = '${@bb.utils.contains("IMAGE_FSTYPES", "overlay", "image-overlay", "", d)}'
+inherit ${IMAGE_TYPE_overlay}
diff --git a/classes/obmc-phosphor-debug-tarball.bbclass b/classes/obmc-phosphor-debug-tarball.bbclass
index 0e5dbd2..a7d2dc4 100644
--- a/classes/obmc-phosphor-debug-tarball.bbclass
+++ b/classes/obmc-phosphor-debug-tarball.bbclass
@@ -1,7 +1,11 @@
+# IMAGE_FSTYPES must appear before image.bbclass
+# is inherited otherwise image.bbclass will inherit
+# "live" image fstypes that we don't want.
+IMAGE_FSTYPES = "tar.xz"
+
 inherit image
 inherit obmc-phosphor-license
 
-IMAGE_FSTYPES = "tar.xz"
 IMAGE_INSTALL_append = " busybox packagegroup-obmc-phosphor-debugtools"
 
 # Override from image_types.bbclass to restrict tarball to /usr tree.
diff --git a/classes/obmc-phosphor-image.bbclass b/classes/obmc-phosphor-image.bbclass
index 4758c8a..9b0a547 100644
--- a/classes/obmc-phosphor-image.bbclass
+++ b/classes/obmc-phosphor-image.bbclass
@@ -95,14 +95,6 @@
 
 OBMC_IMAGE_EXTRA_INSTALL ?= ""
 
-def image_overlay_enabled(d, ifEnabledStr):
-        if d.getVar('OBMC_PHOSPHOR_IMAGE_OVERLAY', True) != "1":
-            return ""
-        return ifEnabledStr
-
-IMAGE_FSTYPES += "${@image_overlay_enabled(d, "overlay")}"
-inherit ${@image_overlay_enabled(d, "image-overlay")}
-
 do_image_complete[depends] += "obmc-phosphor-debug-tarball:do_image_complete"
 
 # The /etc/version file is misleading and not useful.  Remove it.