diff --git a/changelog/change_mark_unsafe_autocorrect_for_style_identical_conditional_branches.mdb b/changelog/change_mark_unsafe_autocorrect_for_style_identical_conditional_branches.mdb
new file mode 100644
index 00000000000..fcfe42759d5
--- /dev/null
+++ b/changelog/change_mark_unsafe_autocorrect_for_style_identical_conditional_branches.mdb
@@ -0,0 +1 @@
+* [#9985](https://github.com/rubocop/rubocop/pull/9985): Mark `Style/IdenticalConditionalBranches` as unsafe auto-correction. ([@koic][])
diff --git a/config/default.yml b/config/default.yml
index c4231cde358..f797bb86da6 100644
--- a/config/default.yml
+++ b/config/default.yml
@@ -3604,8 +3604,9 @@ Style/IdenticalConditionalBranches:
                  line at the end of each branch, which can validly be moved
                  out of the conditional.
   Enabled: true
+  SafeAutoCorrect: false
   VersionAdded: '0.36'
-  VersionChanged: '1.16'
+  VersionChanged: '<<next>>'
 
 Style/IfInsideElse:
   Description: 'Finds if nodes inside else, which can be converted to elsif.'
diff --git a/lib/rubocop/cop/style/identical_conditional_branches.rb b/lib/rubocop/cop/style/identical_conditional_branches.rb
index 0eaf35d3367..bdd43cf01d8 100644
--- a/lib/rubocop/cop/style/identical_conditional_branches.rb
+++ b/lib/rubocop/cop/style/identical_conditional_branches.rb
@@ -7,6 +7,22 @@ module Style
       # each branch of a conditional expression. Such expressions should normally
       # be placed outside the conditional expression - before or after it.
       #
+      # This cop is marked unsafe auto-correction as the order of method invocations
+      # must be guaranteed in the following case:
+      #
+      # [source,ruby]
+      # ----
+      # if method_that_modifies_global_state # 1
+      #   method_that_relies_on_global_state # 2
+      #   foo                                # 3
+      # else
+      #   method_that_relies_on_global_state # 2
+      #   bar                                # 3
+      # end
+      # ----
+      #
+      # In such a case, auto-correction may change the invocation order.
+      #
       # NOTE: The cop is poorly named and some people might think that it actually
       # checks for duplicated conditional branches. The name will probably be changed
       # in a future major RuboCop release.