diff --git a/ip.go b/ip.go
index 746eefd..baa442b 100644
--- a/ip.go
+++ b/ip.go
@@ -3,8 +3,11 @@
 import (
 	"fmt"
 	"net"
+	"strings"
 )
 
+var _ = strings.TrimSpace
+
 // -- net.IP value
 type ipValue net.IP
 
@@ -15,7 +18,7 @@
 
 func (i *ipValue) String() string { return net.IP(*i).String() }
 func (i *ipValue) Set(s string) error {
-	ip := net.ParseIP(s)
+	ip := net.ParseIP(strings.TrimSpace(s))
 	if ip == nil {
 		return fmt.Errorf("failed to parse IP: %q", s)
 	}
diff --git a/ip_test.go b/ip_test.go
new file mode 100644
index 0000000..1fec50e
--- /dev/null
+++ b/ip_test.go
@@ -0,0 +1,63 @@
+package pflag
+
+import (
+	"fmt"
+	"net"
+	"os"
+	"testing"
+)
+
+func setUpIP(ip *net.IP) *FlagSet {
+	f := NewFlagSet("test", ContinueOnError)
+	f.IPVar(ip, "address", net.ParseIP("0.0.0.0"), "IP Address")
+	return f
+}
+
+func TestIP(t *testing.T) {
+	testCases := []struct {
+		input    string
+		success  bool
+		expected string
+	}{
+		{"0.0.0.0", true, "0.0.0.0"},
+		{" 0.0.0.0 ", true, "0.0.0.0"},
+		{"1.2.3.4", true, "1.2.3.4"},
+		{"127.0.0.1", true, "127.0.0.1"},
+		{"255.255.255.255", true, "255.255.255.255"},
+		{"", false, ""},
+		{"0", false, ""},
+		{"localhost", false, ""},
+		{"0.0.0", false, ""},
+		{"0.0.0.", false, ""},
+		{"0.0.0.0.", false, ""},
+		{"0.0.0.256", false, ""},
+		{"0 . 0 . 0 . 0", false, ""},
+	}
+
+	devnull, _ := os.Open(os.DevNull)
+	os.Stderr = devnull
+	for i := range testCases {
+		var addr net.IP
+		f := setUpIP(&addr)
+
+		tc := &testCases[i]
+
+		arg := fmt.Sprintf("--address=%s", tc.input)
+		err := f.Parse([]string{arg})
+		if err != nil && tc.success == true {
+			t.Errorf("expected success, got %q", err)
+			continue
+		} else if err == nil && tc.success == false {
+			t.Errorf("expected failure")
+			continue
+		} else if tc.success {
+			ip, err := f.GetIP("address")
+			if err != nil {
+				t.Errorf("Got error trying to fetch the IP flag: %v", err)
+			}
+			if ip.String() != tc.expected {
+				t.Errorf("expected %q, got %q", tc.expected, ip.String())
+			}
+		}
+	}
+}