diff --git a/Makefile.pre.in b/Makefile.pre.in
index f803391346bd62..d89886ddc76f17 100644
--- a/Makefile.pre.in
+++ b/Makefile.pre.in
@@ -580,7 +580,7 @@ LIBEXPAT_HEADERS= \
 all:		@DEF_MAKE_ALL_RULE@
 build_all:	check-clean-src $(BUILDPYTHON) oldsharedmods sharedmods gdbhooks \
 		Programs/_testembed python-config
-build_platform: check-clean-src $(BUILDPYTHON) platform
+build_wasm: check-clean-src $(BUILDPYTHON) platform oldsharedmods python-config
 
 # Check that the source is clean when building out of source.
 check-clean-src:
@@ -2475,7 +2475,7 @@ update-config:
 Python/thread.o: @THREADHEADERS@ $(srcdir)/Python/condvar.h
 
 # Declare targets that aren't real files
-.PHONY: all build_all sharedmods check-clean-src oldsharedmods test quicktest
+.PHONY: all build_all build_wasm sharedmods check-clean-src oldsharedmods test quicktest
 .PHONY: install altinstall oldsharedinstall bininstall altbininstall
 .PHONY: maninstall libinstall inclinstall libainstall sharedinstall
 .PHONY: frameworkinstall frameworkinstallframework frameworkinstallstructure
diff --git a/configure b/configure
index 96530325f8cb98..26a891ee7fa03a 100755
--- a/configure
+++ b/configure
@@ -7226,8 +7226,8 @@ fi
 
       ;;
   esac
-elif test "$ac_sys_system" = "Emscripten"; then
-      DEF_MAKE_ALL_RULE="build_platform"
+elif test "$ac_sys_system" = "Emscripten" -o "$ac_sys_system" = "WASI"; then
+      DEF_MAKE_ALL_RULE="build_wasm"
   REQUIRE_PGO="no"
   DEF_MAKE_RULE="all"
 else
@@ -7791,17 +7791,17 @@ fi
 case $ac_sys_system/$ac_sys_emscripten_target in #(
   Emscripten/browser*) :
 
-    LDFLAGS_NODIST="$LDFLAGS_NODIST -sALLOW_MEMORY_GROWTH=1"
+    LDFLAGS_NODIST="$LDFLAGS_NODIST -sALLOW_MEMORY_GROWTH"
     LINKFORSHARED="--preload-file=\$(WASM_ASSETS_DIR)"
     if test "x$enable_wasm_dynamic_linking" = xyes; then :
 
-      as_fn_append LINKFORSHARED " -sMAIN_MODULE=1"
+      as_fn_append LINKFORSHARED " -sMAIN_MODULE"
 
 fi
     WASM_ASSETS_DIR=".\$(prefix)"
     WASM_STDLIB="\$(WASM_ASSETS_DIR)/local/lib/python\$(VERSION)/os.py"
         if test "$Py_DEBUG" = 'true' -o "$ac_sys_emscripten_target" = "browser-debug"; then
-      LDFLAGS_NODIST="$LDFLAGS_NODIST -sASSERTIONS=1"
+      LDFLAGS_NODIST="$LDFLAGS_NODIST -sASSERTIONS"
       LINKFORSHARED="$LINKFORSHARED -gsource-map --emit-symbol-map"
     else
       LINKFORSHARED="$LINKFORSHARED -O2 -g0"
@@ -7809,16 +7809,16 @@ fi
    ;; #(
   Emscripten/node*) :
 
-    LDFLAGS_NODIST="$LDFLAGS_NODIST -sALLOW_MEMORY_GROWTH=1 -sNODERAWFS=1 -sUSE_PTHREADS=1"
-    LINKFORSHARED="-sPROXY_TO_PTHREAD=1 -sEXIT_RUNTIME=1"
+    LDFLAGS_NODIST="$LDFLAGS_NODIST -sALLOW_MEMORY_GROWTH -sNODERAWFS -sUSE_PTHREADS"
+    LINKFORSHARED="-sPROXY_TO_PTHREAD -sEXIT_RUNTIME"
     if test "x$enable_wasm_dynamic_linking" = xyes; then :
 
-      as_fn_append LINKFORSHARED " -sMAIN_MODULE=1"
+      as_fn_append LINKFORSHARED " -sMAIN_MODULE"
 
 fi
     CFLAGS_NODIST="$CFLAGS_NODIST -pthread"
     if test "$Py_DEBUG" = 'true' -o "$ac_sys_emscripten_target" = "node-debug"; then
-      LDFLAGS_NODIST="$LDFLAGS_NODIST -sASSERTIONS=1"
+      LDFLAGS_NODIST="$LDFLAGS_NODIST -sASSERTIONS"
       LINKFORSHARED="$LINKFORSHARED -gseparate-dwarf --emit-symbol-map"
     else
       LINKFORSHARED="$LINKFORSHARED -O2 -g0"
@@ -10567,7 +10567,7 @@ fi;;
 fi
 
 if test "$enable_wasm_dynamic_linking" = "yes" -a "$ac_sys_system" = "Emscripten"; then
-  BLDSHARED='$(CC) -shared -sSIDE_MODULE=1 -sWASM=1'
+  BLDSHARED='$(CC) -shared -sSIDE_MODULE=1'
 fi
 
 { $as_echo "$as_me:${as_lineno-$LINENO}: result: $LDSHARED" >&5
@@ -16030,8 +16030,8 @@ $as_echo "yes" >&6; }
 fi
 
 if test "$have_zlib" = "yes" -a "$ac_sys_system" = "Emscripten" -a "$ZLIB_LIBS" = "-lz"; then
-  ZLIB_CFLAGS="-sUSE_ZLIB=1"
-  ZLIB_LIBS="-sUSE_ZLIB=1"
+  ZLIB_CFLAGS="-sUSE_ZLIB"
+  ZLIB_LIBS="-sUSE_ZLIB"
 fi
 
 if test "x$have_zlib" = xyes; then :
@@ -16264,8 +16264,8 @@ $as_echo "yes" >&6; }
 fi
 
 if test "$have_bzip2" = "yes" -a "$ac_sys_system" = "Emscripten" -a "$BZIP2_LIBS" = "-lbz2"; then
-  BZIP2_CFLAGS="-sUSE_BZIP2=1"
-  BZIP2_LIBS="-sUSE_BZIP2=1"
+  BZIP2_CFLAGS="-sUSE_BZIP2"
+  BZIP2_LIBS="-sUSE_BZIP2"
 fi
 
 
@@ -22341,28 +22341,27 @@ $as_echo_n "checking for --disable-test-modules... " >&6; }
 # Check whether --enable-test-modules was given.
 if test "${enable_test_modules+set}" = set; then :
   enableval=$enable_test_modules;
+  if test "x$enable_test_modules" = xyes; then :
+  TEST_MODULES=yes
+else
+  TEST_MODULES=no
 fi
 
-if test "$enable_test_modules" = no; then
-    TEST_MODULES=no
 else
-    case $ac_sys_system/$ac_sys_emscripten_target in #(
+
+  case $ac_sys_system/$ac_sys_emscripten_target in #(
   Emscripten/browser*) :
     TEST_MODULES=no ;; #(
   *) :
     TEST_MODULES=yes
-     ;;
+   ;;
 esac
-fi
-if test "x$TEST_MODULES" = xyes; then :
-  { $as_echo "$as_me:${as_lineno-$LINENO}: result: no" >&5
-$as_echo "no" >&6; }
-else
-  { $as_echo "$as_me:${as_lineno-$LINENO}: result: yes" >&5
-$as_echo "yes" >&6; }
 
 fi
 
+{ $as_echo "$as_me:${as_lineno-$LINENO}: result: $TEST_MODULES" >&5
+$as_echo "$TEST_MODULES" >&6; }
+
 
 
 
diff --git a/configure.ac b/configure.ac
index 6a460cd94c2433..5c915d1a45cdc2 100644
--- a/configure.ac
+++ b/configure.ac
@@ -1574,10 +1574,10 @@ if test "$Py_OPT" = 'true' ; then
       ])
       ;;
   esac
-elif test "$ac_sys_system" = "Emscripten"; then
+elif test "$ac_sys_system" = "Emscripten" -o "$ac_sys_system" = "WASI"; then
   dnl Emscripten does not support shared extensions yet. Build
-  dnl "python.[js,html,wasm]", "pybuilddir.txt", and "platform" files.
-  DEF_MAKE_ALL_RULE="build_platform"
+  dnl "python.[js,wasm]", "pybuilddir.txt", and "platform" files.
+  DEF_MAKE_ALL_RULE="build_wasm"
   REQUIRE_PGO="no"
   DEF_MAKE_RULE="all"
 else
@@ -1911,30 +1911,30 @@ fi
 # WASM flags
 AS_CASE([$ac_sys_system/$ac_sys_emscripten_target],
   [Emscripten/browser*], [
-    LDFLAGS_NODIST="$LDFLAGS_NODIST -sALLOW_MEMORY_GROWTH=1"
+    LDFLAGS_NODIST="$LDFLAGS_NODIST -sALLOW_MEMORY_GROWTH"
     LINKFORSHARED="--preload-file=\$(WASM_ASSETS_DIR)"
     AS_VAR_IF([enable_wasm_dynamic_linking], [yes], [
-      AS_VAR_APPEND([LINKFORSHARED], [" -sMAIN_MODULE=1"])
+      AS_VAR_APPEND([LINKFORSHARED], [" -sMAIN_MODULE"])
     ])
     WASM_ASSETS_DIR=".\$(prefix)"
     WASM_STDLIB="\$(WASM_ASSETS_DIR)/local/lib/python\$(VERSION)/os.py"
     dnl separate-dwarf does not seem to work in Chrome DevTools Support.
     if test "$Py_DEBUG" = 'true' -o "$ac_sys_emscripten_target" = "browser-debug"; then
-      LDFLAGS_NODIST="$LDFLAGS_NODIST -sASSERTIONS=1"
+      LDFLAGS_NODIST="$LDFLAGS_NODIST -sASSERTIONS"
       LINKFORSHARED="$LINKFORSHARED -gsource-map --emit-symbol-map"
     else
       LINKFORSHARED="$LINKFORSHARED -O2 -g0"
     fi
   ],
   [Emscripten/node*], [
-    LDFLAGS_NODIST="$LDFLAGS_NODIST -sALLOW_MEMORY_GROWTH=1 -sNODERAWFS=1 -sUSE_PTHREADS=1"
-    LINKFORSHARED="-sPROXY_TO_PTHREAD=1 -sEXIT_RUNTIME=1"
+    LDFLAGS_NODIST="$LDFLAGS_NODIST -sALLOW_MEMORY_GROWTH -sNODERAWFS -sUSE_PTHREADS"
+    LINKFORSHARED="-sPROXY_TO_PTHREAD -sEXIT_RUNTIME"
     AS_VAR_IF([enable_wasm_dynamic_linking], [yes], [
-      AS_VAR_APPEND([LINKFORSHARED], [" -sMAIN_MODULE=1"])
+      AS_VAR_APPEND([LINKFORSHARED], [" -sMAIN_MODULE"])
     ])
     CFLAGS_NODIST="$CFLAGS_NODIST -pthread"
     if test "$Py_DEBUG" = 'true' -o "$ac_sys_emscripten_target" = "node-debug"; then
-      LDFLAGS_NODIST="$LDFLAGS_NODIST -sASSERTIONS=1"
+      LDFLAGS_NODIST="$LDFLAGS_NODIST -sASSERTIONS"
       LINKFORSHARED="$LINKFORSHARED -gseparate-dwarf --emit-symbol-map"
     else
       LINKFORSHARED="$LINKFORSHARED -O2 -g0"
@@ -3009,7 +3009,7 @@ fi
 dnl Emscripten's emconfigure sets LDSHARED. Set BLDSHARED outside the
 dnl test -z $LDSHARED block to configure BLDSHARED for side module support.
 if test "$enable_wasm_dynamic_linking" = "yes" -a "$ac_sys_system" = "Emscripten"; then
-  BLDSHARED='$(CC) -shared -sSIDE_MODULE=1 -sWASM=1'
+  BLDSHARED='$(CC) -shared -sSIDE_MODULE=1'
 fi
 
 AC_MSG_RESULT($LDSHARED)
@@ -4549,8 +4549,8 @@ PKG_CHECK_MODULES([ZLIB], [zlib >= 1.2.0], [
 ])
 
 if test "$have_zlib" = "yes" -a "$ac_sys_system" = "Emscripten" -a "$ZLIB_LIBS" = "-lz"; then
-  ZLIB_CFLAGS="-sUSE_ZLIB=1"
-  ZLIB_LIBS="-sUSE_ZLIB=1"
+  ZLIB_CFLAGS="-sUSE_ZLIB"
+  ZLIB_LIBS="-sUSE_ZLIB"
 fi
 
 dnl binascii can use zlib for optimized crc32.
@@ -4572,8 +4572,8 @@ PKG_CHECK_MODULES([BZIP2], [bzip2], [have_bzip2=yes], [
 ])
 
 if test "$have_bzip2" = "yes" -a "$ac_sys_system" = "Emscripten" -a "$BZIP2_LIBS" = "-lbz2"; then
-  BZIP2_CFLAGS="-sUSE_BZIP2=1"
-  BZIP2_LIBS="-sUSE_BZIP2=1"
+  BZIP2_CFLAGS="-sUSE_BZIP2"
+  BZIP2_LIBS="-sUSE_BZIP2"
 fi
 
 
@@ -6557,21 +6557,18 @@ fi],
 
 # Check whether to disable test modules. Once set, setup.py will not build
 # test extension modules and "make install" will not install test suites.
-AC_MSG_CHECKING(for --disable-test-modules)
-AC_ARG_ENABLE(test-modules,
-              AS_HELP_STRING([--disable-test-modules], [don't build nor install test modules]))
-if test "$enable_test_modules" = no; then
-    TEST_MODULES=no
-else
-    AS_CASE([$ac_sys_system/$ac_sys_emscripten_target],
-      [Emscripten/browser*], [TEST_MODULES=no],
-      [TEST_MODULES=yes]
-    )
-fi
-AS_VAR_IF([TEST_MODULES], [yes],
-  [AC_MSG_RESULT(no)], [AC_MSG_RESULT(yes)]
-)
-AC_SUBST(TEST_MODULES)
+AC_MSG_CHECKING([for --disable-test-modules])
+AC_ARG_ENABLE([test-modules],
+  [AS_HELP_STRING([--disable-test-modules], [don't build nor install test modules])], [
+  AS_VAR_IF([enable_test_modules], [yes], [TEST_MODULES=yes], [TEST_MODULES=no])
+], [
+  AS_CASE([$ac_sys_system/$ac_sys_emscripten_target],
+    [Emscripten/browser*], [TEST_MODULES=no],
+    [TEST_MODULES=yes]
+  )
+])
+AC_MSG_RESULT([$TEST_MODULES])
+AC_SUBST([TEST_MODULES])
 
 AC_DEFUN([PY_STDLIB_MOD_SET_NA], [
   m4_foreach([mod], [$@], [