diff --git a/src/cmd/go/internal/envcmd/env.go b/src/cmd/go/internal/envcmd/env.go
index 59d0ded658..b5a48558fa 100644
--- a/src/cmd/go/internal/envcmd/env.go
+++ b/src/cmd/go/internal/envcmd/env.go
@@ -424,6 +424,11 @@ func checkEnvWrite(key, val string) error {
 		if !filepath.IsAbs(val) && val != "" {
 			return fmt.Errorf("GOPATH entry is relative; must be absolute path: %q", val)
 		}
+	// Make sure CC and CXX are absolute paths
+	case "CC", "CXX":
+		if !filepath.IsAbs(val) && val != "" && val != filepath.Base(val) {
+			return fmt.Errorf("%s entry is relative; must be absolute path: %q", key, val)
+		}
 	}
 
 	if !utf8.ValidString(val) {
diff --git a/src/cmd/go/internal/work/init.go b/src/cmd/go/internal/work/init.go
index bab1935aca..81c4fb7465 100644
--- a/src/cmd/go/internal/work/init.go
+++ b/src/cmd/go/internal/work/init.go
@@ -41,6 +41,13 @@ func BuildInit() {
 		cfg.BuildPkgdir = p
 	}
 
+	// Make sure CC and CXX are absolute paths
+	for _, key := range []string{"CC", "CXX"} {
+		if path := cfg.Getenv(key); !filepath.IsAbs(path) && path != "" && path != filepath.Base(path) {
+			base.Fatalf("go %s: %s environment variable is relative; must be absolute path: %s\n", flag.Args()[0], key, path)
+		}
+	}
+
 	// For each experiment that has been enabled in the toolchain, define a
 	// build tag with the same name but prefixed by "goexperiment." which can be
 	// used for compiling alternative files for the experiment. This allows
diff --git a/src/cmd/go/testdata/script/env_write.txt b/src/cmd/go/testdata/script/env_write.txt
index bdb9bc4077..24bb6f8f59 100644
--- a/src/cmd/go/testdata/script/env_write.txt
+++ b/src/cmd/go/testdata/script/env_write.txt
@@ -123,6 +123,30 @@ go env -w GOTMPDIR=
 go env GOTMPDIR
 stdout ^$
 
+# go env -w rejects relative CC values
+[!windows] go env -w CC=/usr/bin/clang
+go env -w CC=clang
+[!windows] ! go env -w CC=./clang
+[!windows] ! go env -w CC=bin/clang
+[!windows] stderr 'go env -w: CC entry is relative; must be absolute path'
+
+[windows] go env -w CC=$WORK\bin\clang
+[windows] ! go env -w CC=.\clang
+[windows] ! go env -w CC=bin\clang
+[windows] stderr 'go env -w: CC entry is relative; must be absolute path'
+
+# go env -w rejects relative CXX values
+[!windows] go env -w CC=/usr/bin/cpp
+go env -w CXX=cpp
+[!windows] ! go env -w CXX=./cpp
+[!windows] ! go env -w CXX=bin/cpp
+[!windows] stderr 'go env -w: CXX entry is relative; must be absolute path'
+
+[windows] go env -w CXX=$WORK\bin\cpp
+[windows] ! go env -w CXX=.\cpp
+[windows] ! go env -w CXX=bin\cpp
+[windows] stderr 'go env -w: CXX entry is relative; must be absolute path'
+
 # go env -w/-u checks validity of GOOS/ARCH combinations
 env GOOS=
 env GOARCH=