diff --git a/pkg/dart2wasm/tool/compile_benchmark b/pkg/dart2wasm/tool/compile_benchmark
index 32f27a047b5..9095c8d3094 100755
--- a/pkg/dart2wasm/tool/compile_benchmark
+++ b/pkg/dart2wasm/tool/compile_benchmark
@@ -30,6 +30,9 @@ PROG_NAME="$(follow_links "$BASH_SOURCE")"
 PROG_DIR="$(cd "${PROG_NAME%/*}" ; pwd -P)"
 SDK_DIR="$(cd "${PROG_DIR}/../../.." ; pwd -P)"
 
+# Use same binaryen flags as `dart compile exe`
+BINARYEN_FLAGS="$(sed -n '/binaryenFlags =/,/end of binaryenFlags/ p' $SDK_DIR/pkg/dartdev/lib/src/commands/compile.dart  | sed  '1d' | sed '$d' | tr '\n' ' ')"
+
 # Locate build directory, containing executables, snapshots and platform dill.
 if [[ `uname` == 'Darwin' ]]; then
   OUT_DIR="$SDK_DIR/xcodebuild"
@@ -62,7 +65,7 @@ function measure_size() {
 dart2wasm_command=("$DART2WASM" "$1" "$2" $COMPILE_FLAGS)
 
 # Keep in sync with sdk/bin/dart2wasm.
-binaryen_command=("$BINARYEN" -all --closed-world -tnh --type-unfinalizing -O3 --type-ssa --gufa -O3 --type-merging -O1 --type-finalizing "$2" -o "$2")
+binaryen_command=("$BINARYEN" $BINARYEN_FLAGS "$2" -o "$2")
 
 if [ -n "$COMPILE_BENCHMARK_BASE_NAME" ]; then
   measure ${dart2wasm_command[@]}
diff --git a/pkg/dartdev/lib/src/commands/compile.dart b/pkg/dartdev/lib/src/commands/compile.dart
index a2d99b4eb8f..5507a008da8 100644
--- a/pkg/dartdev/lib/src/commands/compile.dart
+++ b/pkg/dartdev/lib/src/commands/compile.dart
@@ -21,6 +21,28 @@ import '../sdk.dart';
 import '../utils.dart';
 import '../vm_interop_handler.dart';
 
+// The unique place where we store dart2wasm binaryen flags.
+//
+// Other uses (e.g. in shell scripts) will grep in this file for the flags. So
+// please keep it as a simple multi-line string of flags.
+final List<String> binaryenFlags = '''
+  --all-features
+  --closed-world
+  --traps-never-happen
+  --type-unfinalizing
+  -O3
+  --type-ssa
+  --gufa
+  -O3
+  --type-merging
+  -O1
+  --type-finalizing
+''' // end of binaryenFlags
+    .split('\n')
+    .map((line) => line.trim())
+    .where((line) => line.isNotEmpty)
+    .toList();
+
 const int compileErrorExitCode = 64;
 
 class Option {
@@ -394,10 +416,14 @@ class CompileWasmCommand extends CompileSubcommandCommand {
 
   final String optimizer = path.join(
       binDir.path, 'utils', Platform.isWindows ? 'wasm-opt.exe' : 'wasm-opt');
-  String optimizerFlags(bool outputNames) =>
-      '-all --closed-world -tnh --type-unfinalizing -O3 --type-ssa'
-      ' --gufa -O3 --type-merging -O1 --type-finalizing'
-      '${outputNames ? ' -g' : ''}';
+  String optimizerFlags(bool outputNames) {
+    final flags = [
+      ...binaryenFlags,
+      if (outputNames) '-g',
+    ];
+    return flags.join(' ');
+  }
+
   static const String unoptExtension = '.unopt';
 
   CompileWasmCommand({bool verbose = false})
diff --git a/sdk/bin/dart2wasm b/sdk/bin/dart2wasm
index f6d20d0d6e3..7200b662fe3 100755
--- a/sdk/bin/dart2wasm
+++ b/sdk/bin/dart2wasm
@@ -24,6 +24,9 @@ PROG_NAME="$(follow_links "$BASH_SOURCE")"
 PROG_DIR="$(cd "${PROG_NAME%/*}" ; pwd -P)"
 SDK_DIR="$(cd "${PROG_DIR}/../.." ; pwd -P)"
 
+# Use same binaryen flags as `dart compile exe`
+BINARYEN_FLAGS="$(sed -n '/binaryenFlags =/,/end of binaryenFlags/ p' $SDK_DIR/pkg/dartdev/lib/src/commands/compile.dart  | sed  '1d' | sed '$d' | tr '\n' ' ')"
+
 # Locate build directory, containing executables, snapshots and platform dill.
 if [[ `uname` == 'Darwin' ]]; then
   OUT_DIR="$SDK_DIR/xcodebuild"
@@ -127,7 +130,6 @@ set -e
 "$DART_PRECOMPILED_RUNTIME" "--packages=$DART_ROOT/.packages" "${EXTRA_VM_OPTIONS[@]}" "$SNAPSHOT" "$SDK_ARG" "$PLATFORM_ARG" "${ARGS[@]}"
 
 if [[ "$OPTIMIZED" == 1 ]]; then
-    # Keep optimization parameters after `-g` in sync with pkg/dart2wasm/tool/compile_benchmark.
-    # Last argument must be the .wasm file.
-    "$BIN_DIR"/wasm-opt -g -all --closed-world -tnh --type-unfinalizing -O3 --type-ssa --gufa -O3 --type-merging -O1 --type-finalizing "${ARGS[-1]}" -o "${ARGS[-1]}"
+  # Keep the name section by passing `-g`.
+  "$BIN_DIR"/wasm-opt -g $BINARYEN_FLAGS "${ARGS[-1]}" -o "${ARGS[-1]}"
 fi