diff --git a/agent/config/builder.go b/agent/config/builder.go
index 9ca6092ab4..2eff8fbd84 100644
--- a/agent/config/builder.go
+++ b/agent/config/builder.go
@@ -92,8 +92,7 @@ func Load(opts BuilderOpts, extraHead Source, overrides ...Source) (*RuntimeConf
 // since not all pre-conditions have to be satisfied when performing
 // syntactical tests.
 type Builder struct {
-	// devMode stores the value of the -dev flag, and enables development mode.
-	devMode *bool
+	opts BuilderOpts
 
 	// Head, Sources, and Tail are used to manage the order of the
 	// config sources, as described in the comments above.
@@ -105,15 +104,6 @@ type Builder struct {
 	// parsing the configuration.
 	Warnings []string
 
-	// hostname is a shim for testing, allowing tests to specify a replacement
-	// for os.Hostname.
-	hostname func() (string, error)
-
-	// getPrivateIPv4 and getPublicIPv6 are shims for testing, allowing tests to
-	// specify a replacement for ipaddr.GetPrivateIPv4 and ipaddr.GetPublicIPv6.
-	getPrivateIPv4 func() ([]*net.IPAddr, error)
-	getPublicIPv6  func() ([]*net.IPAddr, error)
-
 	// err contains the first error that occurred during
 	// building the runtime configuration.
 	err error
@@ -135,8 +125,8 @@ func NewBuilder(opts BuilderOpts) (*Builder, error) {
 	}
 
 	b := &Builder{
-		devMode: opts.DevMode,
-		Head:    []Source{DefaultSource(), DefaultEnterpriseSource()},
+		opts: opts,
+		Head: []Source{DefaultSource(), DefaultEnterpriseSource()},
 	}
 
 	if b.boolVal(opts.DevMode) {
@@ -467,14 +457,14 @@ func (b *Builder) Build() (rt RuntimeConfig, err error) {
 		switch {
 		case ipaddr.IsAnyV4(advertiseAddr):
 			addrtyp = "private IPv4"
-			detect = b.getPrivateIPv4
+			detect = b.opts.getPrivateIPv4
 			if detect == nil {
 				detect = ipaddr.GetPrivateIPv4
 			}
 
 		case ipaddr.IsAnyV6(advertiseAddr):
 			addrtyp = "public IPv6"
-			detect = b.getPublicIPv6
+			detect = b.opts.getPublicIPv6
 			if detect == nil {
 				detect = ipaddr.GetPublicIPv6
 			}
@@ -994,7 +984,7 @@ func (b *Builder) Build() (rt RuntimeConfig, err error) {
 		DataDir:                                dataDir,
 		Datacenter:                             datacenter,
 		DefaultQueryTime:                       b.durationVal("default_query_time", c.DefaultQueryTime),
-		DevMode:                                b.boolVal(b.devMode),
+		DevMode:                                b.boolVal(b.opts.DevMode),
 		DisableAnonymousSignature:              b.boolVal(c.DisableAnonymousSignature),
 		DisableCoordinates:                     b.boolVal(c.DisableCoordinates),
 		DisableHostNodeID:                      b.boolVal(c.DisableHostNodeID),
@@ -1900,7 +1890,7 @@ func (b *Builder) tlsCipherSuites(name string, v *string) []uint16 {
 func (b *Builder) nodeName(v *string) string {
 	nodeName := b.stringVal(v)
 	if nodeName == "" {
-		fn := b.hostname
+		fn := b.opts.hostname
 		if fn == nil {
 			fn = os.Hostname
 		}
diff --git a/agent/config/builder_test.go b/agent/config/builder_test.go
index 9be12a4d34..430a959e8c 100644
--- a/agent/config/builder_test.go
+++ b/agent/config/builder_test.go
@@ -172,13 +172,13 @@ func TestBuilder_BuildAndValidate_NodeName(t *testing.T) {
 }
 
 func patchBuilderShims(b *Builder) {
-	b.hostname = func() (string, error) {
+	b.opts.hostname = func() (string, error) {
 		return "thehostname", nil
 	}
-	b.getPrivateIPv4 = func() ([]*net.IPAddr, error) {
+	b.opts.getPrivateIPv4 = func() ([]*net.IPAddr, error) {
 		return []*net.IPAddr{ipAddr("10.0.0.1")}, nil
 	}
-	b.getPublicIPv6 = func() ([]*net.IPAddr, error) {
+	b.opts.getPublicIPv6 = func() ([]*net.IPAddr, error) {
 		return []*net.IPAddr{ipAddr("dead:beef::1")}, nil
 	}
 }
diff --git a/agent/config/flags.go b/agent/config/flags.go
index 77dc2abb38..155e243345 100644
--- a/agent/config/flags.go
+++ b/agent/config/flags.go
@@ -3,6 +3,7 @@ package config
 import (
 	"flag"
 	"fmt"
+	"net"
 	"time"
 )
 
@@ -26,6 +27,15 @@ type BuilderOpts struct {
 
 	// HCL contains an arbitrary config in hcl format.
 	HCL []string
+
+	// hostname is a shim for testing, allowing tests to specify a replacement
+	// for os.Hostname.
+	hostname func() (string, error)
+
+	// getPrivateIPv4 and getPublicIPv6 are shims for testing, allowing tests to
+	// specify a replacement for ipaddr.GetPrivateIPv4 and ipaddr.GetPublicIPv6.
+	getPrivateIPv4 func() ([]*net.IPAddr, error)
+	getPublicIPv6  func() ([]*net.IPAddr, error)
 }
 
 // AddFlags adds the command line flags for the agent.
diff --git a/agent/config/runtime_test.go b/agent/config/runtime_test.go
index 092e75b6a3..12307d6416 100644
--- a/agent/config/runtime_test.go
+++ b/agent/config/runtime_test.go
@@ -4886,13 +4886,13 @@ func testConfig(t *testing.T, tests []configTest, dataDir string) {
 
 				patchBuilderShims(b)
 				if tt.hostname != nil {
-					b.hostname = tt.hostname
+					b.opts.hostname = tt.hostname
 				}
 				if tt.privatev4 != nil {
-					b.getPrivateIPv4 = tt.privatev4
+					b.opts.getPrivateIPv4 = tt.privatev4
 				}
 				if tt.publicv6 != nil {
-					b.getPublicIPv6 = tt.publicv6
+					b.opts.getPublicIPv6 = tt.publicv6
 				}
 
 				// read the source fragements
@@ -4937,9 +4937,7 @@ func testConfig(t *testing.T, tests []configTest, dataDir string) {
 				if err != nil {
 					t.Fatal(err)
 				}
-				x.hostname = b.hostname
-				x.getPrivateIPv4 = func() ([]*net.IPAddr, error) { return []*net.IPAddr{ipAddr("10.0.0.1")}, nil }
-				x.getPublicIPv6 = func() ([]*net.IPAddr, error) { return []*net.IPAddr{ipAddr("dead:beef::1")}, nil }
+				patchBuilderShims(x)
 				expected, err := x.Build()
 				if err != nil {
 					t.Fatalf("build default failed: %s", err)