diff --git a/Makefile b/Makefile
index ea490aa4c..15d67647e 100644
--- a/Makefile
+++ b/Makefile
@@ -1,7 +1,7 @@
 PYODIDE_ROOT=$(abspath .)
 include Makefile.envs
 
-FILEPACKAGER=emsdk/emsdk/emscripten/incoming/tools/file_packager.py
+FILEPACKAGER=emsdk/emsdk/emscripten/tag-1.38.4/tools/file_packager.py
 
 CPYTHONROOT=cpython
 CPYTHONLIB=$(CPYTHONROOT)/installs/python-$(PYVERSION)/lib/python$(PYMINOR)
diff --git a/Makefile.envs b/Makefile.envs
index ad921a1eb..f55c630cd 100644
--- a/Makefile.envs
+++ b/Makefile.envs
@@ -1,10 +1,11 @@
-export PATH := $(PYODIDE_ROOT)/emsdk/emsdk:$(PYODIDE_ROOT)/emsdk/emsdk/clang/fastcomp/build_incoming_64/bin:$(PYODIDE_ROOT)/emsdk/emsdk/node/8.9.1_64bit/bin:$(PYODIDE_ROOT)/emsdk/emsdk/emscripten/incoming:$(PYODIDE_ROOT)/emsdk/emsdk/binaryen/master_64bit_binaryen/bin:$(PATH)
+export PATH := $(PYODIDE_ROOT)/emsdk/emsdk:$(PYODIDE_ROOT)/emsdk/emsdk/clang/tag-e-1.38.4/build_tag-e1.38.4_64/bin:$(PYODIDE_ROOT)/emsdk/emsdk/node/8.9.1_64bit/bin:$(PYODIDE_ROOT)/emsdk/emsdk/emscripten/tag-1.38.4:$(PYODIDE_ROOT)/emsdk/emsdk/binaryen/tag-1.38.4_64bit_binaryen/bin:$(PATH)
+
 
 export EMSDK = $(PYODIDE_ROOT)/emsdk/emsdk
 export EM_CONFIG = $(PYODIDE_ROOT)/emsdk/emsdk/.emscripten
 export EM_CACHE = $(PYODIDE_ROOT)/emsdk/emsdk/.emscripten_cache
-export EMSCRIPTEN = $(PYODIDE_ROOT)/emsdk/emsdk/emscripten/incoming
-export BINARYEN_ROOT = $(PYODIDE_ROOT)/emsdk/emsdk/binaryen/master_64bit_binaryen
+export EMSCRIPTEN = $(PYODIDE_ROOT)/emsdk/emsdk/emscripten/tag-1.38.4
+export BINARYEN_ROOT = $(PYODIDE_ROOT)/emsdk/emsdk/binaryen/tag-1.38.4_64bit_binaryen
 
 export PYVERSION=3.6.4
 export PYMINOR=$(basename $(PYVERSION))
@@ -15,6 +16,7 @@ export PLATFORMSLUG=$(shell $(HOSTPYTHON) -c "import sysconfig; print(sysconfig.
 
 export SIDE_LDFLAGS=\
 	-O3 \
+  -s "BINARYEN_METHOD='native-wasm'" \
 	-Werror \
   -s EMULATED_FUNCTION_POINTERS=1 \
   -s EMULATE_FUNCTION_POINTER_CASTS=1 \
diff --git a/emsdk/Makefile b/emsdk/Makefile
index 124194bdd..36b7fcc3f 100644
--- a/emsdk/Makefile
+++ b/emsdk/Makefile
@@ -4,12 +4,12 @@ emsdk/emsdk:
 	git clone https://github.com/juj/emsdk.git
 	( \
 		cd emsdk ; \
-		./emsdk install --build=Release sdk-incoming-64bit binaryen-master-64bit ; \
+		./emsdk install --build=Release sdk-tag-1.38.4-64bit binaryen-tag-1.38.4-64bit ; \
 		cd .. ; \
 		(cat patches/*.patch | patch -p1) ; \
 		cd emsdk ; \
-		./emsdk install --build=Release sdk-incoming-64bit binaryen-master-64bit ; \
-		./emsdk activate --embedded --build=Release sdk-incoming-64bit binaryen-master-64bit \
+		./emsdk install --build=Release sdk-tag-1.37.39-64bit binaryen-tag-1.38.4-64bit ; \
+		./emsdk activate --embedded --build=Release sdk-tag-1.38.4-64bit binaryen-tag-1.38.4-64bit \
 	)
 
 clean:
diff --git a/emsdk/patches/num_params.patch b/emsdk/patches/num_params.patch
index eb060425b..da53a234e 100644
--- a/emsdk/patches/num_params.patch
+++ b/emsdk/patches/num_params.patch
@@ -1,7 +1,7 @@
 diff --git a/emsdk/binaryen/master/src/passes/FuncCastEmulation.cpp b/emsdk/binaryen/master/src/passes/FuncCastEmulation.cpp
 index 013e9403..d95fc282 100644
---- a/emsdk/binaryen/master/src/passes/FuncCastEmulation.cpp
-+++ b/emsdk/binaryen/master/src/passes/FuncCastEmulation.cpp
+--- a/emsdk/binaryen/tag-1.38.4/src/passes/FuncCastEmulation.cpp
++++ b/emsdk/binaryen/tag-1.38.4/src/passes/FuncCastEmulation.cpp
 @@ -39,7 +39,7 @@ namespace wasm {
  // This should be enough for everybody. (As described above, we need this
  // to match when dynamically linking, and also dynamic linking is why we