diff --git a/lang/mruby/Makefile b/lang/mruby/Makefile
index 91d019e0ace..2835c25cfcb 100644
--- a/lang/mruby/Makefile
+++ b/lang/mruby/Makefile
@@ -4,9 +4,7 @@ COMMENT =		lightweight, embeddable implementation of ruby
 
 GH_ACCOUNT =		mruby
 GH_PROJECT =		mruby
-GH_TAGNAME =		3.3.0
-
-REVISION =		2
+GH_TAGNAME =		3.4.0
 
 CATEGORIES =		lang
 HOMEPAGE =		https://mruby.org/
@@ -27,6 +25,7 @@ NO_CONFIGURE =		Yes
 SUBST_VARS =		RUBY
 
 do-build:
+	${SUBST_CMD} ${WRKSRC}/lib/mruby/build/command.rb
 	cd ${WRKSRC} && ${SETENV} ${MAKE_ENV} ${RAKE} --verbose
 
 do-install:
diff --git a/lang/mruby/distinfo b/lang/mruby/distinfo
index 2a596c6cf1a..cb5efbf96c4 100644
--- a/lang/mruby/distinfo
+++ b/lang/mruby/distinfo
@@ -1,2 +1,2 @@
-SHA256 (mruby-3.3.0.tar.gz) = UwiDZ+PXZX63It36y5OPdK7R+FOLNxf+C2649YQCr2U=
-SIZE (mruby-3.3.0.tar.gz) = 833221
+SHA256 (mruby-3.4.0.tar.gz) = GDcRx6JtkytTQuZIYNFpU/HMZRjQeywwoCk3+zYlY/g=
+SIZE (mruby-3.4.0.tar.gz) = 843682
diff --git a/lang/mruby/patches/patch-lib_mruby_build_rb b/lang/mruby/patches/patch-lib_mruby_build_rb
index 803977a413d..a3fa9095afd 100644
--- a/lang/mruby/patches/patch-lib_mruby_build_rb
+++ b/lang/mruby/patches/patch-lib_mruby_build_rb
@@ -1,7 +1,7 @@
 Index: lib/mruby/build.rb
 --- lib/mruby/build.rb.orig
 +++ lib/mruby/build.rb
-@@ -467,7 +467,7 @@ EOS
+@@ -477,7 +477,7 @@ EOS
        mrbc = @gems["mruby-bin-mrbc"] ? exefile("#{@build_dir}/bin/mrbc") : mrbcfile
        env = {"BUILD_DIR" => @build_dir, "MRBCFILE" => mrbc}
        bintest = File.join(MRUBY_ROOT, "test/bintest.rb")
diff --git a/lang/mruby/pkg/PLIST b/lang/mruby/pkg/PLIST
index ce24ca6187c..1a8c58d80d2 100644
--- a/lang/mruby/pkg/PLIST
+++ b/lang/mruby/pkg/PLIST
@@ -25,6 +25,7 @@ include/mruby/internal.h
 include/mruby/irep.h
 include/mruby/istruct.h
 include/mruby/khash.h
+include/mruby/mempool.h
 include/mruby/numeric.h
 include/mruby/object.h
 include/mruby/opcode.h
@@ -159,6 +160,8 @@ lib/mruby/mrbgems/mruby-compar-ext/
 lib/mruby/mrbgems/mruby-compar-ext/mrbgem.rake
 lib/mruby/mrbgems/mruby-compar-ext/mrblib/
 lib/mruby/mrbgems/mruby-compar-ext/mrblib/compar.rb
+lib/mruby/mrbgems/mruby-compar-ext/test/
+lib/mruby/mrbgems/mruby-compar-ext/test/compar.rb
 lib/mruby/mrbgems/mruby-compiler/
 lib/mruby/mrbgems/mruby-compiler/core/
 lib/mruby/mrbgems/mruby-compiler/core/codegen.c
@@ -194,6 +197,13 @@ lib/mruby/mrbgems/mruby-dir/src/dir.c
 lib/mruby/mrbgems/mruby-dir/test/
 lib/mruby/mrbgems/mruby-dir/test/dir.rb
 lib/mruby/mrbgems/mruby-dir/test/dirtest.c
+lib/mruby/mrbgems/mruby-encoding/
+lib/mruby/mrbgems/mruby-encoding/mrbgem.rake
+lib/mruby/mrbgems/mruby-encoding/src/
+lib/mruby/mrbgems/mruby-encoding/src/encoding.c
+lib/mruby/mrbgems/mruby-encoding/test/
+lib/mruby/mrbgems/mruby-encoding/test/numeric.rb
+lib/mruby/mrbgems/mruby-encoding/test/string.rb
 lib/mruby/mrbgems/mruby-enum-chain/
 lib/mruby/mrbgems/mruby-enum-chain/mrbgem.rake
 lib/mruby/mrbgems/mruby-enum-chain/mrblib/
@@ -330,6 +340,7 @@ lib/mruby/mrbgems/mruby-object-ext/src/object.c
 lib/mruby/mrbgems/mruby-object-ext/test/
 lib/mruby/mrbgems/mruby-object-ext/test/nil.rb
 lib/mruby/mrbgems/mruby-object-ext/test/object.rb
+lib/mruby/mrbgems/mruby-object-ext/test/object-ext.c
 lib/mruby/mrbgems/mruby-objectspace/
 lib/mruby/mrbgems/mruby-objectspace/mrbgem.rake
 lib/mruby/mrbgems/mruby-objectspace/src/
@@ -349,12 +360,6 @@ lib/mruby/mrbgems/mruby-pack/src/
 lib/mruby/mrbgems/mruby-pack/src/pack.c
 lib/mruby/mrbgems/mruby-pack/test/
 lib/mruby/mrbgems/mruby-pack/test/pack.rb
-lib/mruby/mrbgems/mruby-print/
-lib/mruby/mrbgems/mruby-print/mrbgem.rake
-lib/mruby/mrbgems/mruby-print/mrblib/
-lib/mruby/mrbgems/mruby-print/mrblib/print.rb
-lib/mruby/mrbgems/mruby-print/src/
-lib/mruby/mrbgems/mruby-print/src/print.c
 lib/mruby/mrbgems/mruby-proc-binding/
 lib/mruby/mrbgems/mruby-proc-binding/mrbgem.rake
 lib/mruby/mrbgems/mruby-proc-binding/src/