diff --git a/src/path/filepath/path_test.go b/src/path/filepath/path_test.go
index bc5509b49c..55b27f1af8 100644
--- a/src/path/filepath/path_test.go
+++ b/src/path/filepath/path_test.go
@@ -791,6 +791,8 @@ var winisabstests = []IsAbsTest{
 	{`c:a\b`, false},
 	{`c:\a\b`, true},
 	{`c:/a/b`, true},
+	{`\\host\share`, true},
+	{`\\host\share\`, true},
 	{`\\host\share\foo`, true},
 	{`//host/share/foo/bar`, true},
 }
diff --git a/src/path/filepath/path_windows.go b/src/path/filepath/path_windows.go
index 445c868e41..b4d8ac3301 100644
--- a/src/path/filepath/path_windows.go
+++ b/src/path/filepath/path_windows.go
@@ -45,6 +45,10 @@ func IsAbs(path string) (b bool) {
 	if l == 0 {
 		return false
 	}
+	// If the volume name starts with a double slash, this is a UNC path.
+	if isSlash(path[0]) && isSlash(path[1]) {
+		return true
+	}
 	path = path[l:]
 	if path == "" {
 		return false