diff --git a/plugins/ipam/host-local/backend/allocator/config.go b/plugins/ipam/host-local/backend/allocator/config.go
index a5ea3b08..ec8bf639 100644
--- a/plugins/ipam/host-local/backend/allocator/config.go
+++ b/plugins/ipam/host-local/backend/allocator/config.go
@@ -57,11 +57,11 @@ type IPAMConfig struct {
 
 type IPAMEnvArgs struct {
 	types.CommonArgs
-	IP net.IP `json:"ip,omitempty"`
+	IP ip.IP `json:"ip,omitempty"`
 }
 
 type IPAMArgs struct {
-	IPs []net.IP `json:"ips"`
+	IPs []*ip.IP `json:"ips"`
 }
 
 type RangeSet []Range
@@ -84,8 +84,7 @@ func LoadIPAMConfig(bytes []byte, envArgs string) (*IPAMConfig, string, error) {
 		return nil, "", fmt.Errorf("IPAM config missing 'ipam' key")
 	}
 
-	// Parse custom IP from env args, the top-level args config and capabilities
-	// in runtime configuration
+	// parse custom IP from env args
 	if envArgs != "" {
 		e := IPAMEnvArgs{}
 		err := types.LoadArgs(envArgs, &e)
@@ -93,15 +92,19 @@ func LoadIPAMConfig(bytes []byte, envArgs string) (*IPAMConfig, string, error) {
 			return nil, "", err
 		}
 
-		if e.IP != nil {
-			n.IPAM.IPArgs = []net.IP{e.IP}
+		if e.IP.ToIP() != nil {
+			n.IPAM.IPArgs = []net.IP{e.IP.ToIP()}
 		}
 	}
 
+	// parse custom IPs from CNI args in network config
 	if n.Args != nil && n.Args.A != nil && len(n.Args.A.IPs) != 0 {
-		n.IPAM.IPArgs = append(n.IPAM.IPArgs, n.Args.A.IPs...)
+		for _, i := range n.Args.A.IPs {
+			n.IPAM.IPArgs = append(n.IPAM.IPArgs, i.ToIP())
+		}
 	}
 
+	// parse custom IPs from runtime configuration
 	if len(n.RuntimeConfig.IPs) > 0 {
 		for _, i := range n.RuntimeConfig.IPs {
 			n.IPAM.IPArgs = append(n.IPAM.IPArgs, i.ToIP())
diff --git a/plugins/ipam/host-local/backend/allocator/config_test.go b/plugins/ipam/host-local/backend/allocator/config_test.go
index b6d7c1db..4c0e0a89 100644
--- a/plugins/ipam/host-local/backend/allocator/config_test.go
+++ b/plugins/ipam/host-local/backend/allocator/config_test.go
@@ -205,8 +205,9 @@ var _ = Describe("IPAM config", func() {
 		}))
 	})
 
-	It("Should parse CNI_ARGS env", func() {
-		input := `{
+	Context("Should parse CNI_ARGS env", func() {
+		It("without prefix", func() {
+			input := `{
 			"cniVersion": "0.3.1",
 			"name": "mynet",
 			"type": "ipvlan",
@@ -224,16 +225,43 @@ var _ = Describe("IPAM config", func() {
 			}
 		}`
 
-		envArgs := "IP=10.1.2.10"
+			envArgs := "IP=10.1.2.10"
 
-		conf, _, err := LoadIPAMConfig([]byte(input), envArgs)
-		Expect(err).NotTo(HaveOccurred())
-		Expect(conf.IPArgs).To(Equal([]net.IP{{10, 1, 2, 10}}))
+			conf, _, err := LoadIPAMConfig([]byte(input), envArgs)
+			Expect(err).NotTo(HaveOccurred())
+			Expect(conf.IPArgs).To(Equal([]net.IP{{10, 1, 2, 10}}))
+		})
 
+		It("with prefix", func() {
+			input := `{
+			"cniVersion": "0.3.1",
+			"name": "mynet",
+			"type": "ipvlan",
+			"master": "foo0",
+			"ipam": {
+				"type": "host-local",
+				"ranges": [[
+					{
+						"subnet": "10.1.2.0/24",
+						"rangeStart": "10.1.2.9",
+						"rangeEnd": "10.1.2.20",
+						"gateway": "10.1.2.30"
+					}
+				]]
+			}
+		}`
+
+			envArgs := "IP=10.1.2.11/24"
+
+			conf, _, err := LoadIPAMConfig([]byte(input), envArgs)
+			Expect(err).NotTo(HaveOccurred())
+			Expect(conf.IPArgs).To(Equal([]net.IP{{10, 1, 2, 11}}))
+		})
 	})
 
-	It("Should parse config args", func() {
-		input := `{
+	Context("Should parse config args", func() {
+		It("without prefix", func() {
+			input := `{
 			"cniVersion": "0.3.1",
 			"name": "mynet",
 			"type": "ipvlan",
@@ -265,16 +293,62 @@ var _ = Describe("IPAM config", func() {
 			}
 		}`
 
-		envArgs := "IP=10.1.2.10"
+			envArgs := "IP=10.1.2.10"
 
-		conf, _, err := LoadIPAMConfig([]byte(input), envArgs)
-		Expect(err).NotTo(HaveOccurred())
-		Expect(conf.IPArgs).To(Equal([]net.IP{
-			{10, 1, 2, 10},
-			{10, 1, 2, 11},
-			{11, 11, 11, 11},
-			net.ParseIP("2001:db8:1::11"),
-		}))
+			conf, _, err := LoadIPAMConfig([]byte(input), envArgs)
+			Expect(err).NotTo(HaveOccurred())
+			Expect(conf.IPArgs).To(Equal([]net.IP{
+				{10, 1, 2, 10},
+				{10, 1, 2, 11},
+				{11, 11, 11, 11},
+				net.ParseIP("2001:db8:1::11"),
+			}))
+		})
+
+		It("with prefix", func() {
+			input := `{
+			"cniVersion": "0.3.1",
+			"name": "mynet",
+			"type": "ipvlan",
+			"master": "foo0",
+			"args": {
+				"cni": {
+					"ips": [ "10.1.2.11/24", "11.11.11.11/24", "2001:db8:1::11/64"]
+				}
+			},
+			"ipam": {
+				"type": "host-local",
+				"ranges": [
+					[{
+						"subnet": "10.1.2.0/24",
+						"rangeStart": "10.1.2.9",
+						"rangeEnd": "10.1.2.20",
+						"gateway": "10.1.2.30"
+					}],
+					[{
+						"subnet": "11.1.2.0/24",
+						"rangeStart": "11.1.2.9",
+						"rangeEnd": "11.1.2.20",
+						"gateway": "11.1.2.30"
+					}],
+					[{
+						"subnet": "2001:db8:1::/64"
+					}]
+				]
+			}
+		}`
+
+			envArgs := "IP=10.1.2.10/24"
+
+			conf, _, err := LoadIPAMConfig([]byte(input), envArgs)
+			Expect(err).NotTo(HaveOccurred())
+			Expect(conf.IPArgs).To(Equal([]net.IP{
+				{10, 1, 2, 10},
+				{10, 1, 2, 11},
+				{11, 11, 11, 11},
+				net.ParseIP("2001:db8:1::11"),
+			}))
+		})
 	})
 
 	It("Should detect overlap between rangesets", func() {