diff --git a/agent/envoyextensions/builtin/http/localratelimit/ratelimit.go b/agent/envoyextensions/builtin/http/localratelimit/ratelimit.go
index 7761982604..07e981ae2d 100644
--- a/agent/envoyextensions/builtin/http/localratelimit/ratelimit.go
+++ b/agent/envoyextensions/builtin/http/localratelimit/ratelimit.go
@@ -60,6 +60,9 @@ func (r *ratelimit) fromArguments(args map[string]interface{}) error {
 	if err := mapstructure.Decode(args, r); err != nil {
 		return fmt.Errorf("error decoding extension arguments: %v", err)
 	}
+	if r.ProxyType == "" {
+		r.ProxyType = string(api.ServiceKindConnectProxy)
+	}
 	return r.validate()
 }
 
@@ -188,7 +191,7 @@ func (r ratelimit) PatchFilter(p extensioncommon.FilterPayload) (*envoy_listener
 }
 
 func validateProxyType(t string) error {
-	if t != "connect-proxy" {
+	if t != string(api.ServiceKindConnectProxy) {
 		return fmt.Errorf("unexpected ProxyType %q", t)
 	}
 
diff --git a/agent/envoyextensions/builtin/http/localratelimit/ratelimit_test.go b/agent/envoyextensions/builtin/http/localratelimit/ratelimit_test.go
index 4d8344ad1d..2b208bf3e7 100644
--- a/agent/envoyextensions/builtin/http/localratelimit/ratelimit_test.go
+++ b/agent/envoyextensions/builtin/http/localratelimit/ratelimit_test.go
@@ -111,6 +111,30 @@ func TestConstructor(t *testing.T) {
 			expectedErrMsg: "cannot parse 'FilterEnforced', -1 overflows uint",
 			ok:             false,
 		},
+		"invalid proxy type": {
+			arguments: makeArguments(map[string]interface{}{
+				"ProxyType":     "invalid",
+				"FillInterval":  30,
+				"MaxTokens":     20,
+				"TokensPerFill": 5,
+			}),
+			expectedErrMsg: `unexpected ProxyType "invalid"`,
+			ok:             false,
+		},
+		"default proxy type": {
+			arguments: makeArguments(map[string]interface{}{
+				"FillInterval":  30,
+				"MaxTokens":     20,
+				"TokensPerFill": 5,
+			}),
+			expected: ratelimit{
+				ProxyType:     "connect-proxy",
+				MaxTokens:     intPointer(20),
+				FillInterval:  intPointer(30),
+				TokensPerFill: intPointer(5),
+			},
+			ok: true,
+		},
 		"valid everything": {
 			arguments: makeArguments(map[string]interface{}{
 				"ProxyType":     "connect-proxy",
diff --git a/agent/envoyextensions/builtin/lua/lua.go b/agent/envoyextensions/builtin/lua/lua.go
index 8293228a79..aefea37e6c 100644
--- a/agent/envoyextensions/builtin/lua/lua.go
+++ b/agent/envoyextensions/builtin/lua/lua.go
@@ -45,6 +45,9 @@ func (l *lua) fromArguments(args map[string]interface{}) error {
 	if err := mapstructure.Decode(args, l); err != nil {
 		return fmt.Errorf("error decoding extension arguments: %v", err)
 	}
+	if l.ProxyType == "" {
+		l.ProxyType = string(api.ServiceKindConnectProxy)
+	}
 	return l.validate()
 }
 
@@ -53,7 +56,7 @@ func (l *lua) validate() error {
 	if l.Script == "" {
 		resultErr = multierror.Append(resultErr, fmt.Errorf("missing Script value"))
 	}
-	if l.ProxyType != "connect-proxy" {
+	if l.ProxyType != string(api.ServiceKindConnectProxy) {
 		resultErr = multierror.Append(resultErr, fmt.Errorf("unexpected ProxyType %q", l.ProxyType))
 	}
 	if l.Listener != "inbound" && l.Listener != "outbound" {
diff --git a/agent/envoyextensions/builtin/lua/lua_test.go b/agent/envoyextensions/builtin/lua/lua_test.go
index d80a3b333a..3ea2ba716c 100644
--- a/agent/envoyextensions/builtin/lua/lua_test.go
+++ b/agent/envoyextensions/builtin/lua/lua_test.go
@@ -54,6 +54,15 @@ func TestConstructor(t *testing.T) {
 			arguments: makeArguments(map[string]interface{}{"Listener": "invalid"}),
 			ok:        false,
 		},
+		"default proxy type": {
+			arguments: makeArguments(map[string]interface{}{"ProxyType": ""}),
+			expected: lua{
+				ProxyType: "connect-proxy",
+				Listener:  "inbound",
+				Script:    "lua-script",
+			},
+			ok: true,
+		},
 		"valid everything": {
 			arguments: makeArguments(map[string]interface{}{}),
 			expected: lua{
diff --git a/agent/envoyextensions/builtin/property-override/property_override.go b/agent/envoyextensions/builtin/property-override/property_override.go
index 8164a8092a..51d7836852 100644
--- a/agent/envoyextensions/builtin/property-override/property_override.go
+++ b/agent/envoyextensions/builtin/property-override/property_override.go
@@ -261,6 +261,9 @@ func (p *propertyOverride) validate() error {
 		}
 	}
 
+	if p.ProxyType == "" {
+		p.ProxyType = api.ServiceKindConnectProxy
+	}
 	if err := validProxyTypes.CheckRequired(string(p.ProxyType), "ProxyType"); err != nil {
 		resultErr = multierror.Append(resultErr, err)
 	}
diff --git a/agent/envoyextensions/builtin/property-override/property_override_test.go b/agent/envoyextensions/builtin/property-override/property_override_test.go
index ca549353fa..21889d840f 100644
--- a/agent/envoyextensions/builtin/property-override/property_override_test.go
+++ b/agent/envoyextensions/builtin/property-override/property_override_test.go
@@ -236,7 +236,7 @@ func TestConstructor(t *testing.T) {
 		// enforces expected behavior until we do. Multi-member slices should be unaffected
 		// by WeakDecode as it is a more-permissive version of the default behavior.
 		"single value Patches decoded as map construction succeeds": {
-			arguments: makeArguments(map[string]any{"Patches": makePatch(map[string]any{})}),
+			arguments: makeArguments(map[string]any{"Patches": makePatch(map[string]any{}), "ProxyType": nil}),
 			expected:  validTestCase(OpAdd, extensioncommon.TrafficDirectionOutbound, ResourceTypeRoute).expected,
 			ok:        true,
 		},