diff --git a/configure b/configure
index 8cf777e..263719f 100755
--- a/configure
+++ b/configure
@@ -3202,6 +3202,9 @@ then
 	*-*-cygwin*)
 		ac_sys_system=Cygwin
 		;;
+	asmjs-*-*)
+		ac_sys_system=Emscripten
+		;;
 	*)
 		# for now, limit cross builds to known configurations
 		MACHDEP="unknown"
@@ -3248,6 +3251,9 @@ if test "$cross_compiling" = yes; then
 	*-*-cygwin*)
 		_host_cpu=
 		;;
+	asmjs-*-*)
+		_host_cpu=
+		;;
 	*)
 		# for now, limit cross builds to known configurations
 		MACHDEP="unknown"
diff --git a/configure.ac b/configure.ac
index 78fe3c7..d7665b4 100644
--- a/configure.ac
+++ b/configure.ac
@@ -322,6 +322,9 @@ then
 	*-*-cygwin*)
 		ac_sys_system=Cygwin
 		;;
+	asmjs-*-*)
+		ac_sys_system=Emscripten
+		;;
 	*)
 		# for now, limit cross builds to known configurations
 		MACHDEP="unknown"
@@ -368,6 +371,9 @@ if test "$cross_compiling" = yes; then
 	*-*-cygwin*)
 		_host_cpu=
 		;;
+	asmjs-*-*)
+		_host_cpu=
+		;;
 	*)
 		# for now, limit cross builds to known configurations
 		MACHDEP="unknown"
diff --git a/config.sub b/config.sub
index d654d03..0d8236f 100755
--- a/config.sub
+++ b/config.sub
@@ -119,7 +119,8 @@ case $maybe_os in
   linux-musl* | linux-uclibc* | uclinux-uclibc* | uclinux-gnu* | kfreebsd*-gnu* | \
   knetbsd*-gnu* | netbsd*-gnu* | \
   kopensolaris*-gnu* | cloudabi*-eabi* | \
-  storm-chaos* | os2-emx* | rtmk-nova*)
+  storm-chaos* | os2-emx* | rtmk-nova* | \
+  emscripten)
     os=-$maybe_os
     basic_machine=`echo $1 | sed 's/^\(.*\)-\([^-]*-[^-]*\)$/\1/'`
     ;;
@@ -254,6 +255,7 @@ case $basic_machine in
 	| am33_2.0 \
 	| arc | arceb \
 	| arm | arm[bl]e | arme[lb] | armv[2-8] | armv[3-8][lb] | armv7[arm] \
+	| asmjs \
 	| avr | avr32 \
 	| be32 | be64 \
 	| bfin \
@@ -1510,6 +1512,8 @@ case $os in
 	-dicos*)
 		os=-dicos
 		;;
+	-emscripten)
+		;;
 	-nacl*)
 		;;
 	-none)