diff --git a/lib/bundler/definition.rb b/lib/bundler/definition.rb
index c8faf77b3b..b402bc50de 100644
--- a/lib/bundler/definition.rb
+++ b/lib/bundler/definition.rb
@@ -92,11 +92,12 @@ module Bundler
         @platforms = @locked_platforms.dup
         @locked_bundler_version = @locked_gems.bundler_version
         @locked_ruby_version = @locked_gems.ruby_version
+        @originally_locked_deps = @locked_gems.dependencies
         @originally_locked_specs = SpecSet.new(@locked_gems.specs)
         @locked_checksums = @locked_gems.checksums
 
         if unlock != true
-          @locked_deps    = @locked_gems.dependencies
+          @locked_deps    = @originally_locked_deps
           @locked_specs   = @originally_locked_specs
           @locked_sources = @locked_gems.sources
         else
@@ -111,6 +112,7 @@ module Bundler
         @locked_gems    = nil
         @locked_deps    = {}
         @locked_specs   = SpecSet.new([])
+        @originally_locked_deps = {}
         @originally_locked_specs = @locked_specs
         @locked_sources = []
         @locked_platforms = []
@@ -835,9 +837,7 @@ module Bundler
           dep.source = sources.get(dep.source)
         end
 
-        next if unlocking?
-
-        unless locked_dep = @locked_deps[dep.name]
+        unless locked_dep = @originally_locked_deps[dep.name]
           changes = true
           next
         end
diff --git a/spec/bundler/commands/update_spec.rb b/spec/bundler/commands/update_spec.rb
index cfb86ebb54..8565e27ebf 100644
--- a/spec/bundler/commands/update_spec.rb
+++ b/spec/bundler/commands/update_spec.rb
@@ -1954,6 +1954,52 @@ RSpec.describe "bundle update conservative" do
     end
   end
 
+  context "when Gemfile dependencies have changed" do
+    before do
+      build_repo4 do
+        build_gem "nokogiri", "1.16.4" do |s|
+          s.platform = "arm64-darwin"
+        end
+
+        build_gem "nokogiri", "1.16.4" do |s|
+          s.platform = "x86_64-linux"
+        end
+
+        build_gem "prism", "0.25.0"
+      end
+
+      gemfile <<~G
+        source "#{file_uri_for(gem_repo4)}"
+        gem "nokogiri", ">=1.16.4"
+        gem "prism", ">=0.25.0"
+      G
+
+      lockfile <<~L
+        GEM
+          remote: #{file_uri_for(gem_repo4)}/
+          specs:
+            nokogiri (1.16.4-arm64-darwin)
+            nokogiri (1.16.4-x86_64-linux)
+
+        PLATFORMS
+          arm64-darwin
+          x86_64-linux
+
+        DEPENDENCIES
+          nokogiri (>= 1.16.4)
+
+        BUNDLED WITH
+           #{Bundler::VERSION}
+      L
+    end
+
+    it "still works" do
+      simulate_platform "arm64-darwin-23" do
+        bundle "update"
+      end
+    end
+  end
+
   context "error handling" do
     before do
       gemfile "source \"#{file_uri_for(gem_repo1)}\""