diff --git a/build/Cargo.lock b/build/Cargo.lock
index 3f9003c..39a3427 100644
--- a/build/Cargo.lock
+++ b/build/Cargo.lock
@@ -123,17 +123,17 @@ dependencies = [
 
 [[package]]
 name = "parity-wasm"
-version = "0.18.0"
+version = "0.23.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 dependencies = [
  "byteorder 1.1.0 (registry+https://github.com/rust-lang/crates.io-index)",
  "log 0.3.8 (registry+https://github.com/rust-lang/crates.io-index)",
- "parking_lot 0.4.8 (registry+https://github.com/rust-lang/crates.io-index)",
+ "parking_lot 0.5.3 (registry+https://github.com/rust-lang/crates.io-index)",
 ]
 
 [[package]]
 name = "parking_lot"
-version = "0.4.8"
+version = "0.5.3"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 dependencies = [
  "owning_ref 0.3.3 (registry+https://github.com/rust-lang/crates.io-index)",
@@ -275,7 +275,7 @@ version = "0.1.0"
 dependencies = [
  "clap 2.27.1 (registry+https://github.com/rust-lang/crates.io-index)",
  "glob 0.2.11 (registry+https://github.com/rust-lang/crates.io-index)",
- "parity-wasm 0.18.0 (registry+https://github.com/rust-lang/crates.io-index)",
+ "parity-wasm 0.23.0 (registry+https://github.com/rust-lang/crates.io-index)",
  "tempdir 0.3.5 (registry+https://github.com/rust-lang/crates.io-index)",
  "wasm-utils 0.1.0",
 ]
@@ -290,7 +290,7 @@ dependencies = [
  "glob 0.2.11 (registry+https://github.com/rust-lang/crates.io-index)",
  "lazy_static 0.2.10 (registry+https://github.com/rust-lang/crates.io-index)",
  "log 0.3.8 (registry+https://github.com/rust-lang/crates.io-index)",
- "parity-wasm 0.18.0 (registry+https://github.com/rust-lang/crates.io-index)",
+ "parity-wasm 0.23.0 (registry+https://github.com/rust-lang/crates.io-index)",
 ]
 
 [[package]]
@@ -321,8 +321,8 @@ source = "registry+https://github.com/rust-lang/crates.io-index"
 "checksum log 0.3.8 (registry+https://github.com/rust-lang/crates.io-index)" = "880f77541efa6e5cc74e76910c9884d9859683118839d6a1dc3b11e63512565b"
 "checksum memchr 1.0.2 (registry+https://github.com/rust-lang/crates.io-index)" = "148fab2e51b4f1cfc66da2a7c32981d1d3c083a803978268bb11fe4b86925e7a"
 "checksum owning_ref 0.3.3 (registry+https://github.com/rust-lang/crates.io-index)" = "cdf84f41639e037b484f93433aa3897863b561ed65c6e59c7073d7c561710f37"
-"checksum parity-wasm 0.18.0 (registry+https://github.com/rust-lang/crates.io-index)" = "f02e35fda913b8873799b817dcab145d1f935a900722ab7274027949d9947a56"
-"checksum parking_lot 0.4.8 (registry+https://github.com/rust-lang/crates.io-index)" = "149d8f5b97f3c1133e3cfcd8886449959e856b557ff281e292b733d7c69e005e"
+"checksum parity-wasm 0.23.0 (registry+https://github.com/rust-lang/crates.io-index)" = "b1ba4b1d4236b76694f6ab8d8d00cdbe1e37c6dd1b5c803d26721f27e097d4d9"
+"checksum parking_lot 0.5.3 (registry+https://github.com/rust-lang/crates.io-index)" = "3e7f7c9857874e54afeb950eebeae662b1e51a2493666d2ea4c0a5d91dcf0412"
 "checksum parking_lot_core 0.2.6 (registry+https://github.com/rust-lang/crates.io-index)" = "4f610cb9664da38e417ea3225f23051f589851999535290e077939838ab7a595"
 "checksum rand 0.3.18 (registry+https://github.com/rust-lang/crates.io-index)" = "6475140dfd8655aeb72e1fd4b7a1cc1c202be65d71669476e392fe62532b9edd"
 "checksum redox_syscall 0.1.31 (registry+https://github.com/rust-lang/crates.io-index)" = "8dde11f18c108289bef24469638a04dce49da56084f2d50618b226e47eb04509"
diff --git a/src/optimizer.rs b/src/optimizer.rs
index e856286..b8d9a82 100644
--- a/src/optimizer.rs
+++ b/src/optimizer.rs
@@ -26,6 +26,9 @@ pub fn optimize(
 		}
 	}
 
+	// If there is start function in module, it should stary
+	module.start_section().map(|ss| stay.insert(Symbol::Function(ss as usize)));
+
 	// All symbols used in data/element segments are also should be preserved
 	let mut init_symbols = Vec::new();
 	if let Some(data_section) = module.data_section() {