diff --git a/aegisub/tools/Makefile b/aegisub/tools/Makefile
index 6bc78bd28..20045143b 100644
--- a/aegisub/tools/Makefile
+++ b/aegisub/tools/Makefile
@@ -11,6 +11,13 @@ CLEANFILES += osx-bundle-restart-helper
 all: osx-bundle-restart-helper
 endif
 
+CXXFLAGS +=  -I../libaegisub/include $(CFLAGS_ICU)
+LIBS := -L../libaegisub -laegisub $(LIBS)
+LIBS += $(LIBS_BOOST) $(LIBS_ICU) $(LIBS_LUA)
+
+repack-thes-dict: repack-thes-dict.cpp
+	$(BIN_CXX) -o repack-thes-dict repack-thes-dict.cpp  $(CXXFLAGS) $(LIBS)
+
 EXTRA_DIST = \
 	osx-bundle-restart-helper.c \
 	osx-bundle.sh \
diff --git a/aegisub/tools/repack-thes-dict.cpp b/aegisub/tools/repack-thes-dict.cpp
new file mode 100644
index 000000000..9e2229e8c
--- /dev/null
+++ b/aegisub/tools/repack-thes-dict.cpp
@@ -0,0 +1,91 @@
+// Copyright (c) 2013, Thomas Goyne <plorkyeran@aegisub.org>
+//
+// Permission to use, copy, modify, and distribute this software for any
+// purpose with or without fee is hereby granted, provided that the above
+// copyright notice and this permission notice appear in all copies.
+//
+// THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
+// WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
+// MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
+// ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
+// WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
+// ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
+// OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
+
+#include <libaegisub/charset_conv.h>
+#include <libaegisub/dispatch.h>
+#include <libaegisub/io.h>
+#include <libaegisub/line_iterator.h>
+#include <libaegisub/log.h>
+#include <libaegisub/util.h>
+
+#include <boost/algorithm/string.hpp>
+#include <boost/locale/generator.hpp>
+#include <boost/phoenix/core/argument.hpp>
+#include <boost/phoenix/operator/comparison.hpp>
+#include <fstream>
+
+namespace {
+using boost::phoenix::placeholders::_1;
+
+void convert(std::string const& path) {
+	std::unique_ptr<std::ifstream> idx(agi::io::Open(path + ".idx"));
+	std::unique_ptr<std::ifstream> dat(agi::io::Open(path + ".dat"));
+
+	std::ostringstream idx_out_buffer;
+	agi::io::Save idx_out(path + ".out.idx");
+	agi::io::Save dat_out(path + ".out.dat");
+
+	idx_out.Get() << "UTF-8\n";
+	dat_out.Get() << "UTF-8\n";
+
+	std::string encoding_name;
+	getline(*idx, encoding_name);
+
+	agi::charset::IconvWrapper conv(encoding_name.c_str(), "utf-8");
+
+	std::string unused_entry_count;
+	getline(*idx, unused_entry_count);
+
+	int entry_count = 0;
+
+	for (auto const& line : agi::line_iterator<std::string>(*idx, encoding_name)) {
+		std::vector<std::string> chunks;
+		boost::split(chunks, line, _1 == '|');
+		if (chunks.size() != 2)
+			continue;
+		if (chunks[0].find(' ') != std::string::npos)
+			continue;
+
+		++entry_count;
+
+		idx_out_buffer << chunks[0] << '|' << dat_out.Get().tellp() << '\n';
+		dat->seekg(atoi(chunks[1].c_str()));
+
+		agi::line_iterator<std::string> iter{*dat, encoding_name};
+		dat_out.Get() << *iter << '\n';
+
+		std::vector<std::string> header;
+		boost::split(header, *iter, _1 == '|');
+		int meanings = atoi(header[1].c_str());
+		for (int i = 0; i < meanings; ++i)
+			dat_out.Get() << *++iter << '\n';
+	}
+
+	idx_out.Get() << entry_count << '\n' << idx_out_buffer.str();
+}
+
+}
+
+int main(int argc, char *argv[]) {
+	if (argc != 2) {
+		printf("usage: respack-thes-dict <path-to-dict-without-extension>\n");
+		return 1;
+	}
+	agi::dispatch::Init([](agi::dispatch::Thunk f) { });
+	std::locale::global(boost::locale::generator().generate(""));
+	agi::log::log = new agi::log::LogSink;
+
+	convert(argv[1]);
+}
+