diff --git a/.github/workflows/ci.yml b/.github/workflows/ci.yml
index 1eb7e839..ee95beb3 100644
--- a/.github/workflows/ci.yml
+++ b/.github/workflows/ci.yml
@@ -115,7 +115,7 @@ jobs:
   compatibility-test:
     strategy:
       matrix:
-        go-version: ["1.22.2", "1.21", "1.20"]
+        go-version: ["1.22.2", "1.21"]
         os: [ubuntu-latest, macos-latest, windows-latest]
         arch: ["386", amd64]
         exclude:
diff --git a/Makefile b/Makefile
index a4477c98..d76c365a 100644
--- a/Makefile
+++ b/Makefile
@@ -150,9 +150,9 @@ lint: $(GOLANGCI_LINT) $(MISSPELL) govulncheck
 	done
 	$(MISSPELL) -w $(ALL_DOCS)
 	set -e; for dir in $(ALL_GO_MOD_DIRS) $(TOOLS_MOD_DIR); do \
-	  echo "go mod tidy -compat=1.20 in $${dir}"; \
+	  echo "go mod tidy -compat=1.21 in $${dir}"; \
 	  (cd "$${dir}" && \
-	    go mod tidy -compat=1.20); \
+	    go mod tidy -compat=1.21); \
 	done
 
 generate: $(STRINGER) $(PROTOC)
@@ -191,7 +191,7 @@ govulncheck/%: | $(GOVULNCHECK)
 
 .PHONY: gotidy
 gotidy:
-	$(MAKE) for-all-mod CMD="go mod tidy -compat=1.20"
+	$(MAKE) for-all-mod CMD="go mod tidy -compat=1.21"
 
 .PHONY: update-dep
 update-dep:
diff --git a/detectors/gcp/go.mod b/detectors/gcp/go.mod
index a318b8b4..033c5a57 100644
--- a/detectors/gcp/go.mod
+++ b/detectors/gcp/go.mod
@@ -1,6 +1,6 @@
 module github.com/GoogleCloudPlatform/opentelemetry-operations-go/detectors/gcp
 
-go 1.20
+go 1.21
 
 require (
 	cloud.google.com/go/compute/metadata v0.2.3
diff --git a/go.mod b/go.mod
index afc4ce67..02f399ac 100644
--- a/go.mod
+++ b/go.mod
@@ -1,6 +1,6 @@
 module github.com/GoogleCloudPlatform/opentelemetry-operations-go
 
-go 1.20
+go 1.21
 
 retract (
 	v1.8.0
diff --git a/internal/cloudmock/go.mod b/internal/cloudmock/go.mod
index 983ae327..2a99ade5 100644
--- a/internal/cloudmock/go.mod
+++ b/internal/cloudmock/go.mod
@@ -1,6 +1,6 @@
 module github.com/GoogleCloudPlatform/opentelemetry-operations-go/internal/cloudmock
 
-go 1.20
+go 1.21
 
 require (
 	cloud.google.com/go/logging v1.7.0
diff --git a/internal/cloudmock/go.sum b/internal/cloudmock/go.sum
index 86b5f219..d646d1aa 100644
--- a/internal/cloudmock/go.sum
+++ b/internal/cloudmock/go.sum
@@ -11,6 +11,7 @@ github.com/golang/protobuf v1.5.3 h1:KhyjKVUg7Usr/dYsdSqoFveMYd5ko72D+zANwlG1mmg
 github.com/golang/protobuf v1.5.3/go.mod h1:XVQd3VNwM+JqD3oG2Ue2ip4fOMUkwXdXDdiuN0vRsmY=
 github.com/google/go-cmp v0.5.5/go.mod h1:v8dTdLbMG2kIc/vJvl+f65V22dbkXbowE6jgT/gNBxE=
 github.com/google/go-cmp v0.5.9 h1:O2Tfq5qg4qc4AmwVlvv0oLiVAGB7enBSJ2x2DqQFi38=
+github.com/google/go-cmp v0.5.9/go.mod h1:17dUlkBOakJ0+DkrSSNjCkIjxS6bF9zb3elmeNGIjoY=
 golang.org/x/net v0.23.0 h1:7EYJ93RZ9vYSZAIb2x3lnuvqO5zneoD6IvWjuhfxjTs=
 golang.org/x/net v0.23.0/go.mod h1:JKghWKKOSdJwpW2GEx0Ja7fmaKnMsbu+MWVZTokSYmg=
 golang.org/x/sys v0.18.0 h1:DBdB3niSjOA/O0blCZBqDefyWNYveAYMNF1Wum0DYQ4=
diff --git a/tools/go.mod b/tools/go.mod
index 0fadb807..99718882 100644
--- a/tools/go.mod
+++ b/tools/go.mod
@@ -1,6 +1,6 @@
 module github.com/GoogleCloudPlatform/opentelemetry-operations-go/tools
 
-go 1.20
+go 1.21
 
 require (
 	github.com/client9/misspell v0.3.4