diff --git a/suit_generator/suit/envelope.py b/suit_generator/suit/envelope.py
index c7ccf9e..c446bd8 100644
--- a/suit_generator/suit/envelope.py
+++ b/suit_generator/suit/envelope.py
@@ -24,6 +24,7 @@
     suit_candidate_verification,
     suit_payload_fetch,
     suit_install,
+    suit_install_legacy,
     suit_text,
     suit_integrated_payloads,
     suit_integrated_dependencies,
@@ -42,6 +43,7 @@ class SuitEnvelopeSimplified(SuitKeyValue):
             suit_payload_fetch: SuitBstr,
             suit_candidate_verification: SuitBstr,
             suit_install: SuitBstr,
+            suit_install_legacy: SuitBstr,
             suit_text: SuitBstr,
             suit_integrated_payloads: SuitIntegratedPayloadMap,
             suit_integrated_dependencies: SuitIntegratedPayloadMap,
@@ -62,6 +64,7 @@ class SuitEnvelope(SuitKeyValue):
             suit_payload_fetch: cbstr(SuitCommandSequence),
             suit_candidate_verification: cbstr(SuitCommandSequence),
             suit_install: cbstr(SuitCommandSequence),
+            suit_install_legacy: cbstr(SuitCommandSequence),
             suit_text: cbstr(SuitTextMap),
             suit_integrated_payloads: SuitIntegratedPayloadMap,
             suit_integrated_dependencies: SuitIntegratedPayloadMap,
@@ -104,6 +107,7 @@ def update_severable_digests(self):
             suit_payload_fetch,
             suit_candidate_verification,
             suit_install,
+            suit_install_legacy,
         ]
         for severable_element in severable_elements:
             if severable_element in self.SuitEnvelopeTagged.value.SuitEnvelope[suit_manifest].SuitManifest and hasattr(
diff --git a/suit_generator/suit/manifest.py b/suit_generator/suit/manifest.py
index 5ba5435..67c1e72 100644
--- a/suit_generator/suit/manifest.py
+++ b/suit_generator/suit/manifest.py
@@ -92,6 +92,7 @@
     suit_invoke,
     suit_payload_fetch,
     suit_install,
+    suit_install_legacy,
     suit_text_manifest_description,
     suit_text_manifest_json_source,
     suit_text_manifest_yaml_source,
@@ -468,6 +469,7 @@ class SuitManifest(SuitKeyValue):
             suit_invoke: cbstr(SuitCommandSequence),
             suit_payload_fetch: SuitSeverableCommandSequence,
             suit_install: SuitSeverableCommandSequence,
+            suit_install_legacy: SuitSeverableCommandSequence,
             suit_text: SuitSeverableText,
             suit_dependency_resolution: SuitSeverableCommandSequence,
             suit_candidate_verification: SuitSeverableCommandSequence,
diff --git a/suit_generator/suit/types/keys.py b/suit_generator/suit/types/keys.py
index 8a7bf3d..8fba815 100644
--- a/suit_generator/suit/types/keys.py
+++ b/suit_generator/suit/types/keys.py
@@ -302,10 +302,17 @@ class suit_payload_fetch(suit_key):
     name = "suit-payload-fetch"
 
 
+class suit_install_legacy(suit_key):
+    """suit-install metadata (before v27)."""
+
+    id = 17
+    name = "suit-install-legacy"
+
+
 class suit_install(suit_key):
     """suit-install metadata."""
 
-    id = 17
+    id = 20
     name = "suit-install"
 
 
diff --git a/tests/test_suit_envelope_severable.py b/tests/test_suit_envelope_severable.py
index 1c003ba..429709d 100644
--- a/tests/test_suit_envelope_severable.py
+++ b/tests/test_suit_envelope_severable.py
@@ -376,9 +376,9 @@
     "ENVELOPE_2_SEVERED_TEXT_FETCH_INSTALL": (
         "d86ba602458143822f400358cea601010201035857a2028384414d4218ff451a0e054000451a0005600084414"
         "d410e451a2e054000451a000560008241444100045829840c0114a201507617daa571fd5a858f94e28d735ce9"
-        "f40250d622bafd4337518590bc6368cda7fbca11822f5820f0b65173c03a9c481a0fe3ea62ed744bcfb0bef21"
+        "f40250d622bafd4337518590bc6368cda7fbca14822f5820f0b65173c03a9c481a0fe3ea62ed744bcfb0bef21"
         "43d4380e52dd67d5ee4200d10822f5820814a3a9e09cf691e5fa77c315c0a69a9929ee86601d5dfdca8b24819"
-        "e0be745917822f5820aac171d7a184ecd31c01495ac6b656b2e60a5aa43de6f6d1c9acdac29bb540c211581e9"
+        "e0be745917822f5820aac171d7a184ecd31c01495ac6b656b2e60a5aa43de6f6d1c9acdac29bb540c214581e9"
         "00c0214a115692366696c652e62696e150003000c0114a11602160003001050840c0214a115692366696c652e"
         "62696e175896a162656ea184414d4102451a0e0aa000451a00056000a60178184e6f726469632053656d69636"
         "f6e647563746f7220415341026e6e5246353432305f637075617070036e6e6f7264696373656d692e636f6d04"