.github/workflows/go.yml | 12 ++++++------
 go.mod                   |  2 +-
 go.sum                   |  6 ++++++

diff --git a/.github/workflows/go.yml b/.github/workflows/go.yml
index acb07b2a48c94a03ec85a7ed1c8db1c5f9cef961..e95f82604f5cc5234f91a0cb825a2b98f620fc63 100644
--- a/.github/workflows/go.yml
+++ b/.github/workflows/go.yml
@@ -9,7 +9,7 @@     timeout-minutes: 10
     runs-on: ${{ matrix.os }}
     strategy:
       matrix:
-        go-version: [ '1.21', '1.20' ]
+        go-version: [ '1.21' ]
         os: [windows-latest, macos-latest, ubuntu-latest]
       fail-fast: false
     steps:
@@ -23,7 +23,7 @@   test-benchmarks:
     runs-on: ubuntu-latest
     strategy:
       matrix:
-        go-version: [ '1.20' ]
+        go-version: [ '1.21' ]
       fail-fast: false
     steps:
     - uses: actions/checkout@v2
@@ -34,7 +34,7 @@   bench:
     runs-on: ubuntu-latest
     strategy:
       matrix:
-        go-version: [ '1.20' ]
+        go-version: [ '1.21' ]
       fail-fast: false
     steps:
     - uses: actions/checkout@v2
@@ -45,7 +45,7 @@   test-386:
     runs-on: ubuntu-latest
     strategy:
       matrix:
-        go-version: [ '1.20' ]
+        go-version: [ '1.21' ]
       fail-fast: false
     steps:
     - uses: actions/checkout@v2
@@ -57,7 +57,7 @@   build-wasm:
     runs-on: ubuntu-latest
     strategy:
       matrix:
-        go-version: [ '1.20' ]
+        go-version: [ '1.21' ]
       fail-fast: false
     steps:
     - uses: actions/checkout@v2
@@ -70,7 +70,7 @@     timeout-minutes: 5
     runs-on: ${{ matrix.os }}
     strategy:
       matrix:
-        go-version: [ '1.20' ]
+        go-version: [ '1.21' ]
         os: [ubuntu-latest]
       fail-fast: false
     steps:
diff --git a/go.mod b/go.mod
index 80903fcfaad4d4576080f7751d41acddefe445de..017d7c1a771db15f12f597897b2de91035bee72b 100644
--- a/go.mod
+++ b/go.mod
@@ -19,7 +19,7 @@ 	github.com/anacrolix/missinggo/perf v1.0.0
 	github.com/anacrolix/missinggo/v2 v2.7.2-0.20230527121029-a582b4f397b9
 	github.com/anacrolix/multiless v0.3.0
 	github.com/anacrolix/squirrel v0.6.0
-	github.com/anacrolix/sync v0.4.1-0.20230926072150-b8cd7cfb92d0
+	github.com/anacrolix/sync v0.5.1
 	github.com/anacrolix/tagflag v1.3.0
 	github.com/anacrolix/upnp v0.1.3-0.20220123035249-922794e51c96
 	github.com/anacrolix/utp v0.1.0
diff --git a/go.sum b/go.sum
index 51989f9eeca0a3dc18b0e4efcfec757ca3a42ace..3481257ecd093a443788cb1fd6c483de2b1f169c 100644
--- a/go.sum
+++ b/go.sum
@@ -112,6 +112,12 @@ github.com/anacrolix/sync v0.0.0-20180808010631-44578de4e778/go.mod h1:s735Etp3joe/voe2sdaXLcqDdJSay1O0OPnM0ystjqk=
 github.com/anacrolix/sync v0.3.0/go.mod h1:BbecHL6jDSExojhNtgTFSBcdGerzNc64tz3DCOj/I0g=
 github.com/anacrolix/sync v0.4.1-0.20230926072150-b8cd7cfb92d0 h1:M2HtYrYz6CVwo88TfVrGNlc+mSe59KXCBe3gFuEsEto=
 github.com/anacrolix/sync v0.4.1-0.20230926072150-b8cd7cfb92d0/go.mod h1:BbecHL6jDSExojhNtgTFSBcdGerzNc64tz3DCOj/I0g=
+github.com/anacrolix/sync v0.4.1-0.20231010084430-16a382a507b7 h1:nEKxALDw0bDilJHuXgyeYQ55ldQd5o1MQeFr+DJOg20=
+github.com/anacrolix/sync v0.4.1-0.20231010084430-16a382a507b7/go.mod h1:BbecHL6jDSExojhNtgTFSBcdGerzNc64tz3DCOj/I0g=
+github.com/anacrolix/sync v0.5.0 h1:WGhPVyl4/12Bo/xksj1LadLnR1LeBm+RmJzH0br9XUY=
+github.com/anacrolix/sync v0.5.0/go.mod h1:BbecHL6jDSExojhNtgTFSBcdGerzNc64tz3DCOj/I0g=
+github.com/anacrolix/sync v0.5.1 h1:FbGju6GqSjzVoTgcXTUKkF041lnZkG5P0C3T5RL3SGc=
+github.com/anacrolix/sync v0.5.1/go.mod h1:BbecHL6jDSExojhNtgTFSBcdGerzNc64tz3DCOj/I0g=
 github.com/anacrolix/tagflag v0.0.0-20180109131632-2146c8d41bf0/go.mod h1:1m2U/K6ZT+JZG0+bdMK6qauP49QT4wE5pmhJXOKKCHw=
 github.com/anacrolix/tagflag v1.0.0/go.mod h1:1m2U/K6ZT+JZG0+bdMK6qauP49QT4wE5pmhJXOKKCHw=
 github.com/anacrolix/tagflag v1.1.0/go.mod h1:Scxs9CV10NQatSmbyjqmqmeQNwGzlNe0CMUMIxqHIG8=