diff --git a/pubspec.lock b/pubspec.lock
index 069372c..43c9793 100644
--- a/pubspec.lock
+++ b/pubspec.lock
@@ -14,7 +14,7 @@ packages:
       name: fixnum
       url: "https://pub.dartlang.org"
     source: hosted
-    version: "0.10.11"
+    version: "1.1.0"
   path:
     dependency: "direct main"
     description:
@@ -28,7 +28,7 @@ packages:
       name: protobuf
       url: "https://pub.dartlang.org"
     source: hosted
-    version: "1.1.4"
+    version: "2.0.0"
   retry:
     dependency: "direct main"
     description:
@@ -37,4 +37,4 @@ packages:
     source: hosted
     version: "2.0.0"
 sdks:
-  dart: ">=2.12.0 <3.0.0"
+  dart: ">=2.19.0 <3.0.0"
diff --git a/pubspec.yaml b/pubspec.yaml
index f750506..1ada00a 100644
--- a/pubspec.yaml
+++ b/pubspec.yaml
@@ -4,6 +4,6 @@ environment:
 dependencies:
   collection: ^1.14.13 # Locked to 1.14.13, can update with no unlock.
   retry: ^2.0.0 # Can update with updated constraint, no further constraints.
-  protobuf: 1.1.4 # Can update with updated constraint, only together with fixnum.
-  fixnum: 0.10.11
+  protobuf: ^2.0.0 # Can update with updated constraint, only together with fixnum.
+  fixnum: ^1.1.0
   path: 1.8.1 # Already at latest