diff --git a/drivers/driverutil/util.go b/drivers/driverutil/util.go
index cb43006340..cf36fc5a46 100644
--- a/drivers/driverutil/util.go
+++ b/drivers/driverutil/util.go
@@ -1,23 +1,16 @@
 package driverutil
 
-import (
-	"fmt"
-	"strconv"
-	"strings"
-)
+import "strings"
 
 // SplitPortProto splits a string in the format port/protocol, defaulting
 // protocol to "tcp" if not provided.
-func SplitPortProto(raw string) (port int, protocol string, err error) {
+func SplitPortProto(raw string) (port string, protocol string, err error) {
 	parts := strings.Split(raw, "/")
 	if len(parts) == 1 {
 		protocol = "tcp"
 	} else {
 		protocol = parts[1]
 	}
-	port, err = strconv.Atoi(parts[0])
-	if err != nil {
-		return 0, "", fmt.Errorf("invalid port number %s: %s", parts[0], err)
-	}
+	port = parts[0]
 	return port, protocol, nil
 }
diff --git a/drivers/driverutil/util_test.go b/drivers/driverutil/util_test.go
index c26d533d76..58f1a3a7fb 100644
--- a/drivers/driverutil/util_test.go
+++ b/drivers/driverutil/util_test.go
@@ -9,14 +9,13 @@ import (
 func TestSplitPortProtocol(t *testing.T) {
 	tests := []struct {
 		raw           string
-		expectedPort  int
+		expectedPort  string
 		expectedProto string
 		expectedErr   bool
 	}{
-		{"8080/tcp", 8080, "tcp", false},
-		{"90/udp", 90, "udp", false},
-		{"80", 80, "tcp", false},
-		{"abc", 0, "", true},
+		{"8080/tcp", "8080", "tcp", false},
+		{"90/udp", "90", "udp", false},
+		{"80", "80", "tcp", false},
 	}
 
 	for _, tc := range tests {