diff --git a/benchmark/parse.yaml b/benchmark/parse.yaml
index 8818b50c..8c85ed17 100644
--- a/benchmark/parse.yaml
+++ b/benchmark/parse.yaml
@@ -6,7 +6,7 @@ contexts:
     prelude: require 'rexml'
   - name: master
     gems:
-      strscan: 3.0.8
+      strscan: 3.0.9
     prelude: |
       $LOAD_PATH.unshift(File.expand_path("lib"))
       require 'rexml'
@@ -19,7 +19,7 @@ contexts:
       RubyVM::YJIT.enable
   - name: master(YJIT)
     gems:
-      strscan: 3.0.8
+      strscan: 3.0.9
     prelude: |
       $LOAD_PATH.unshift(File.expand_path("lib"))
       require 'rexml'
diff --git a/lib/rexml/source.rb b/lib/rexml/source.rb
index 71b08f99..db78a124 100644
--- a/lib/rexml/source.rb
+++ b/lib/rexml/source.rb
@@ -149,11 +149,7 @@ def initialize(arg, block_size=500, encoding=nil)
 
     def read
       begin
-        # NOTE: `@scanner << readline` does not free memory, so when parsing huge XML in JRuby's DOM,
-        # out-of-memory error `Java::JavaLang::OutOfMemoryError: Java heap space` occurs.
-        # `@scanner.string = @scanner.rest + readline` frees memory that is already consumed
-        # and avoids this problem.
-        @scanner.string = @scanner.rest + readline
+        @scanner << readline
       rescue Exception, NameError
         @source = nil
       end
diff --git a/rexml.gemspec b/rexml.gemspec
index 2ba1c64d..c76bedbe 100644
--- a/rexml.gemspec
+++ b/rexml.gemspec
@@ -55,7 +55,7 @@ Gem::Specification.new do |spec|
 
   spec.required_ruby_version = '>= 2.5.0'
 
-  spec.add_runtime_dependency("strscan", ">= 3.0.8")
+  spec.add_runtime_dependency("strscan", ">= 3.0.9")
 
   spec.add_development_dependency "benchmark_driver"
   spec.add_development_dependency "bundler"