diff --git a/language/go/fileinfo.go b/language/go/fileinfo.go
index 990f5070f..8e6fe266b 100644
--- a/language/go/fileinfo.go
+++ b/language/go/fileinfo.go
@@ -525,6 +525,9 @@ func matchesOS(os, value string) bool {
 	if os == value {
 		return true
 	}
+	if value == "unix" {
+		return rule.UnixOS[os]
+	}
 	for _, alias := range rule.OSAliases[os] {
 		if alias == value {
 			return true
@@ -556,8 +559,7 @@ func checkConstraints(c *config.Config, os, arch, osSuffix, archSuffix string, t
 		if isIgnoredTag(tag) {
 			return true
 		}
-
-		if _, ok := rule.KnownOSSet[tag]; ok {
+		if _, ok := rule.KnownOSSet[tag]; ok || tag == "unix" {
 			if os == "" {
 				return false
 			}
diff --git a/rule/platform.go b/rule/platform.go
index 2d797672d..fffac4799 100644
--- a/rule/platform.go
+++ b/rule/platform.go
@@ -102,6 +102,23 @@ var OSAliases = map[string][]string{
 	"ios":     {"darwin"},
 }
 
+// UnixOS is the set of GOOS values matched by the "unix" build tag.
+// This list is from go/src/cmd/dist/build.go.
+var UnixOS = map[string]bool{
+	"aix":       true,
+	"android":   true,
+	"darwin":    true,
+	"dragonfly": true,
+	"freebsd":   true,
+	"hurd":      true,
+	"illumos":   true,
+	"ios":       true,
+	"linux":     true,
+	"netbsd":    true,
+	"openbsd":   true,
+	"solaris":   true,
+}
+
 var (
 	// KnownOSs is the sorted list of operating systems that Go supports.
 	KnownOSs []string