diff --git a/Cargo.lock b/Cargo.lock
index 7a550e2..3374aad 100644
--- a/Cargo.lock
+++ b/Cargo.lock
@@ -39,12 +39,6 @@ dependencies = [
  "yansi",
 ]
 
-[[package]]
-name = "ascii"
-version = "0.9.3"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "eab1c04a571841102f5345a8fc0f6bb3d31c315dec879b5c6e42e40ce7ffa34e"
-
 [[package]]
 name = "ascii-canvas"
 version = "3.0.0"
@@ -94,10 +88,10 @@ source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "b4682ae6287fcf752ecaabbfcc7b6f9b72aa33933dc23a554d853aea8eea8635"
 
 [[package]]
-name = "byteorder"
-version = "1.4.3"
+name = "bytes"
+version = "1.6.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "14c189c53d098945499cdfa7ecc63567cf3886b3332b312a5b4585d8d3a6a610"
+checksum = "514de17de45fdb8dc022b1a7975556c53c86f9f0aa5f534b98977b171857c2c9"
 
 [[package]]
 name = "cc"
@@ -131,15 +125,12 @@ dependencies = [
 
 [[package]]
 name = "combine"
-version = "3.8.1"
+version = "4.6.7"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "da3da6baa321ec19e1cc41d31bf599f00c783d0517095cdaf0332e3fe8d20680"
+checksum = "ba5a308b75df32fe02788e748662718f03fde005016435c444eea572398219fd"
 dependencies = [
- "ascii",
- "byteorder",
- "either",
+ "bytes",
  "memchr",
- "unreachable",
 ]
 
 [[package]]
@@ -838,27 +829,12 @@ version = "0.2.4"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "f962df74c8c05a667b5ee8bcf162993134c104e96440b663c8daa176dc772d8c"
 
-[[package]]
-name = "unreachable"
-version = "1.0.0"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "382810877fe448991dfc7f0dd6e3ae5d58088fd0ea5e35189655f84e6814fa56"
-dependencies = [
- "void",
-]
-
 [[package]]
 name = "version_check"
 version = "0.9.4"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "49874b5167b65d7193b8aba1567f5c7d93d001cafc34600cee003eda787e483f"
 
-[[package]]
-name = "void"
-version = "1.0.2"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "6a02e4885ed3bc0f2de90ea6dd45ebcbb66dacffe03547fadbb0eeae2770887d"
-
 [[package]]
 name = "wasi"
 version = "0.11.0+wasi-snapshot-preview1"
diff --git a/examples/combine-app/Cargo.toml b/examples/combine-app/Cargo.toml
index ec79cc2..68dc695 100644
--- a/examples/combine-app/Cargo.toml
+++ b/examples/combine-app/Cargo.toml
@@ -8,4 +8,4 @@ name = "combine-app"
 path = "app.rs"
 
 [dependencies]
-combine = "3.8.1"
+combine = "4.0.0"