diff --git a/CHANGELOG.md b/CHANGELOG.md
index d7c885af02e1..af3ae69e55be 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -16,6 +16,7 @@ Compatibility:
 * Add `MAJOR`, `MINOR`, `TEENY`, `PATCHLEVEL`, `RUBY_API_VERSION`, and `RUBY_PROGRAM_VERSION` to `RbConfig::CONFIG` (#3396, @rwstauner).
 * Set `RbConfig::CONFIG['archincludedir']` (#3396, @andrykonchin).
 * Support the index/length arguments for the string argument to `String#bytesplice` added in 3.3 (#3656, @rwstauner).
+* Implement `rb_str_strlen()` (#3697, @Th3-M4jor).
 
 Performance:
 
diff --git a/lib/cext/include/truffleruby/truffleruby-abi-version.h b/lib/cext/include/truffleruby/truffleruby-abi-version.h
index edde108df446..e819cb98548c 100644
--- a/lib/cext/include/truffleruby/truffleruby-abi-version.h
+++ b/lib/cext/include/truffleruby/truffleruby-abi-version.h
@@ -20,6 +20,6 @@
 // $RUBY_VERSION must be the same as TruffleRuby.LANGUAGE_VERSION.
 // $ABI_NUMBER starts at 1 and is incremented for every ABI-incompatible change.
 
-#define TRUFFLERUBY_ABI_VERSION "3.2.4.3"
+#define TRUFFLERUBY_ABI_VERSION "3.2.4.4"
 
 #endif
diff --git a/spec/ruby/optional/capi/ext/string_spec.c b/spec/ruby/optional/capi/ext/string_spec.c
index cec3f65f458b..94f412267ff7 100644
--- a/spec/ruby/optional/capi/ext/string_spec.c
+++ b/spec/ruby/optional/capi/ext/string_spec.c
@@ -117,6 +117,10 @@ VALUE string_spec_rb_str_cmp(VALUE self, VALUE str1, VALUE str2) {
   return INT2NUM(rb_str_cmp(str1, str2));
 }
 
+VALUE string_spec_rb_str_strlen(VALUE self, VALUE str) {
+  return LONG2NUM(rb_str_strlen(str));
+}
+
 VALUE string_spec_rb_str_conv_enc(VALUE self, VALUE str, VALUE from, VALUE to) {
   rb_encoding* from_enc;
   rb_encoding* to_enc;
@@ -600,6 +604,7 @@ void Init_string_spec(void) {
   rb_define_method(cls, "rb_str_cat_cstr", string_spec_rb_str_cat_cstr, 2);
   rb_define_method(cls, "rb_str_cat_cstr_constant", string_spec_rb_str_cat_cstr_constant, 1);
   rb_define_method(cls, "rb_str_cmp", string_spec_rb_str_cmp, 2);
+  rb_define_method(cls, "rb_str_strlen", string_spec_rb_str_strlen, 1);
   rb_define_method(cls, "rb_str_conv_enc", string_spec_rb_str_conv_enc, 3);
   rb_define_method(cls, "rb_str_conv_enc_opts", string_spec_rb_str_conv_enc_opts, 5);
   rb_define_method(cls, "rb_str_drop_bytes", string_spec_rb_str_drop_bytes, 2);
diff --git a/spec/ruby/optional/capi/string_spec.rb b/spec/ruby/optional/capi/string_spec.rb
index a8edf998b54b..d43dddeacf12 100644
--- a/spec/ruby/optional/capi/string_spec.rb
+++ b/spec/ruby/optional/capi/string_spec.rb
@@ -449,6 +449,20 @@ def inspect
     end
   end
 
+  describe "rb_str_strlen" do
+    it 'returns 0 as the length of an empty string' do
+      @s.rb_str_strlen('').should == 0
+    end
+
+    it 'returns the number of characters in a string' do
+      @s.rb_str_strlen('hello').should == 5
+    end
+
+    it 'returns the number of characters in a string with multi-byte characters' do
+      @s.rb_str_strlen('こんにちは').should == 5
+    end
+  end
+
   describe "rb_str_split" do
     it "splits strings over a splitter" do
       @s.rb_str_split("Hello,Goodbye").should == ["Hello", "Goodbye"]
diff --git a/src/main/c/cext/string.c b/src/main/c/cext/string.c
index a7d95cb7fd1d..96b49287ac39 100644
--- a/src/main/c/cext/string.c
+++ b/src/main/c/cext/string.c
@@ -204,6 +204,10 @@ int rb_str_cmp(VALUE a, VALUE b) {
   return polyglot_as_i32(RUBY_INVOKE_NO_WRAP(a, "<=>", b));
 }
 
+long rb_str_strlen(VALUE string) {
+  return polyglot_as_i64(RUBY_INVOKE_NO_WRAP(string, "size"));
+}
+
 VALUE rb_str_conv_enc(VALUE string, rb_encoding *from, rb_encoding *to) {
   return rb_str_conv_enc_opts(string, from, to, 0, Qnil);
 }