diff --git a/futility/updater.c b/futility/updater.c
index 6a7d8ff..f634c22 100644
--- a/futility/updater.c
+++ b/futility/updater.c
@@ -660,7 +660,7 @@
 /*
  * Returns a valid root key from GBB header, or NULL on failure.
  */
-static const struct vb2_packed_key *get_rootkey(
+const struct vb2_packed_key *get_rootkey(
 		const struct vb2_gbb_header *gbb)
 {
 	struct vb2_packed_key *key = NULL;
@@ -1352,6 +1352,10 @@
 			ERROR("Failed to get system current firmware\n");
 			return 1;
 		}
+		if (get_config_quirk(QUIRK_OVERRIDE_SIGNATURE_ID, cfg) &&
+		    is_write_protection_enabled(cfg))
+			quirk_override_signature_id(
+					cfg, model, &signature_id);
 	}
 	return !!model_apply_white_label(
 			model, cfg->archive, signature_id, tmp_image);
diff --git a/futility/updater.h b/futility/updater.h
index c83ebfc..e11cc74 100644
--- a/futility/updater.h
+++ b/futility/updater.h
@@ -43,6 +43,7 @@
 	QUIRK_EVE_SMM_STORE,
 	QUIRK_ALLOW_EMPTY_WLTAG,
 	QUIRK_EC_PARTIAL_RECOVERY,
+	QUIRK_OVERRIDE_SIGNATURE_ID,
 	QUIRK_MAX,
 };
 
@@ -124,6 +125,12 @@
 extern const char * const updater_error_messages[];
 
 /*
+ * Returns a valid root key from GBB header, or NULL on failure.
+ */
+const struct vb2_packed_key *get_rootkey(
+		const struct vb2_gbb_header *gbb);
+
+/*
  * The main updater to update system firmware using the configuration parameter.
  * Returns UPDATE_ERR_DONE if success, otherwise failure.
  */
@@ -168,6 +175,14 @@
  */
 const char * const updater_get_default_quirks(struct updater_config *cfg);
 
+/*
+ * Overrides signature id if the device was shipped with known
+ * special rootkey.
+ */
+int quirk_override_signature_id(struct updater_config *cfg,
+				struct model_config *model,
+				const char **signature_id);
+
 /* Functions from updater_archive.c */
 
 /*
diff --git a/futility/updater_quirks.c b/futility/updater_quirks.c
index 1dfbedd..a2015f6 100644
--- a/futility/updater_quirks.c
+++ b/futility/updater_quirks.c
@@ -55,6 +55,8 @@
         { .match = "Google_Reks.", .quirks = "allow_empty_wltag" },
         { .match = "Google_Relm.", .quirks = "allow_empty_wltag" },
         { .match = "Google_Wizpig.", .quirks = "allow_empty_wltag" },
+
+        { .match = "Google_Phaser.", .quirks = "override_signature_id" },
 };
 
 /* Preserves meta data and reload image contents from given file path. */
@@ -423,6 +425,12 @@
 	quirks->help = "chromium/1024401; recover EC by partial RO update.";
 	quirks->apply = quirk_ec_partial_recovery;
 	quirks->value = -1;  /* Decide at runtime. */
+
+	quirks = &cfg->quirks[QUIRK_OVERRIDE_SIGNATURE_ID];
+	quirks->name = "override_signature_id";
+	quirks->help = "chromium/146876241; override signature id for "
+			"devices shipped with different root key.";
+	quirks->apply = NULL; /* Simple config. */
 }
 
 /*
@@ -448,3 +456,30 @@
 	}
 	return NULL;
 }
+
+/*
+ * Overrides signature id if the device was shipped with known
+ * special rootkey.
+ */
+int quirk_override_signature_id(struct updater_config *cfg,
+				struct model_config *model,
+				const char **signature_id)
+{
+	const char * const DOPEFISH_KEY_HASH =
+				"9a1f2cc319e2f2e61237dc51125e35ddd4d20984";
+
+	/* b/146876241 */
+	assert(model);
+	if (strcmp(model->name, "phaser360") == 0) {
+		struct firmware_image *image = &cfg->image_current;
+		const char *key_hash = get_firmware_rootkey_hash(image);
+		if (key_hash && strcmp(key_hash, DOPEFISH_KEY_HASH) == 0) {
+			const char * const sig_dopefish = "phaser360-dopefish";
+			WARN("A Phaser360 with Dopefish rootkey - "
+			     "override signature_id to '%s'.\n", sig_dopefish);
+			*signature_id = sig_dopefish;
+		}
+	}
+
+	return 0;
+}
diff --git a/futility/updater_utils.c b/futility/updater_utils.c
index 7a8185b..3807fbb 100644
--- a/futility/updater_utils.c
+++ b/futility/updater_utils.c
@@ -12,6 +12,7 @@
 #include "2common.h"
 #include "crossystem.h"
 #include "host_misc.h"
+#include "util_misc.h"
 #include "updater.h"
 
 #define COMMAND_BUFFER_SIZE 256
@@ -662,3 +663,28 @@
 		free(head);
 	}
 }
+
+/*
+ * Returns rootkey hash of firmware image, or NULL on failure.
+ */
+const char *get_firmware_rootkey_hash(const struct firmware_image *image)
+{
+	const struct vb2_gbb_header *gbb = NULL;
+	const struct vb2_packed_key *rootkey = NULL;
+
+	assert(image->data);
+
+	gbb = find_gbb(image);
+	if (!gbb) {
+		WARN("No GBB found in image.\n");
+		return NULL;
+	}
+
+	rootkey = get_rootkey(gbb);
+	if (!rootkey) {
+		WARN("No rootkey found in image.\n");
+		return NULL;
+	}
+
+	return packed_key_sha1_string(rootkey);
+}
diff --git a/futility/updater_utils.h b/futility/updater_utils.h
index eb455d1..f5248f8 100644
--- a/futility/updater_utils.h
+++ b/futility/updater_utils.h
@@ -207,4 +207,9 @@
 /* Helper function to initialize system properties. */
 void init_system_properties(struct system_property *props, int num);
 
+/*
+ * Returns rootkey hash of firmware image, or NULL on failure.
+ */
+const char *get_firmware_rootkey_hash(const struct firmware_image *image);
+
 #endif  /* VBOOT_REFERENCE_FUTILITY_UPDATER_UTILS_H_ */