diff --git a/cmd/coordinator/coordinator.go b/cmd/coordinator/coordinator.go
index 6a719a52f8..357f36a960 100644
--- a/cmd/coordinator/coordinator.go
+++ b/cmd/coordinator/coordinator.go
@@ -56,7 +56,6 @@ import (
 	"golang.org/x/build/autocertcache"
 	"golang.org/x/build/buildenv"
 	"golang.org/x/build/buildlet"
-	"golang.org/x/build/cmd/coordinator/spanlog"
 	"golang.org/x/build/dashboard"
 	"golang.org/x/build/gerrit"
 	"golang.org/x/build/internal/buildgo"
@@ -64,6 +63,7 @@ import (
 	"golang.org/x/build/internal/secret"
 	"golang.org/x/build/internal/singleflight"
 	"golang.org/x/build/internal/sourcecache"
+	"golang.org/x/build/internal/spanlog"
 	"golang.org/x/build/livelog"
 	"golang.org/x/build/maintner/maintnerd/apipb"
 	"golang.org/x/build/repos"
diff --git a/cmd/coordinator/gce.go b/cmd/coordinator/gce.go
index 03592e5a2c..762a4b5c5d 100644
--- a/cmd/coordinator/gce.go
+++ b/cmd/coordinator/gce.go
@@ -34,13 +34,13 @@ import (
 	"cloud.google.com/go/storage"
 	"golang.org/x/build/buildenv"
 	"golang.org/x/build/buildlet"
-	"golang.org/x/build/cmd/coordinator/spanlog"
 	"golang.org/x/build/dashboard"
 	"golang.org/x/build/gerrit"
 	"golang.org/x/build/internal/buildgo"
 	"golang.org/x/build/internal/buildstats"
 	"golang.org/x/build/internal/lru"
 	"golang.org/x/build/internal/secret"
+	"golang.org/x/build/internal/spanlog"
 	"golang.org/x/oauth2"
 	"golang.org/x/oauth2/google"
 	"google.golang.org/api/compute/v1"
diff --git a/cmd/coordinator/sched.go b/cmd/coordinator/sched.go
index 314f891282..64e8d389bc 100644
--- a/cmd/coordinator/sched.go
+++ b/cmd/coordinator/sched.go
@@ -16,9 +16,9 @@ import (
 	"time"
 
 	"golang.org/x/build/buildlet"
-	"golang.org/x/build/cmd/coordinator/spanlog"
 	"golang.org/x/build/dashboard"
 	"golang.org/x/build/internal/buildgo"
+	"golang.org/x/build/internal/spanlog"
 	"golang.org/x/build/types"
 )
 
diff --git a/cmd/coordinator/sched_test.go b/cmd/coordinator/sched_test.go
index 263606965a..67ba1dfd38 100644
--- a/cmd/coordinator/sched_test.go
+++ b/cmd/coordinator/sched_test.go
@@ -15,8 +15,8 @@ import (
 	"time"
 
 	"golang.org/x/build/buildlet"
-	"golang.org/x/build/cmd/coordinator/spanlog"
 	"golang.org/x/build/dashboard"
+	"golang.org/x/build/internal/spanlog"
 )
 
 func TestSchedLess(t *testing.T) {
diff --git a/cmd/coordinator/spanlog/README.md b/cmd/coordinator/spanlog/README.md
deleted file mode 100644
index 80512c88da..0000000000
--- a/cmd/coordinator/spanlog/README.md
+++ /dev/null
@@ -1,7 +0,0 @@
-<!-- Auto-generated by x/build/update-readmes.go -->
-
-[![GoDoc](https://godoc.org/golang.org/x/build/cmd/coordinator/spanlog?status.svg)](https://godoc.org/golang.org/x/build/cmd/coordinator/spanlog)
-
-# golang.org/x/build/cmd/coordinator/spanlog
-
-Package spanlog provides span and event logger interfaces that are used by the build coordinator infrastructure.
diff --git a/cmd/coordinator/spanlog/spanlog.go b/cmd/coordinator/spanlog/spanlog.go
deleted file mode 100644
index bcf7b3a027..0000000000
--- a/cmd/coordinator/spanlog/spanlog.go
+++ /dev/null
@@ -1,31 +0,0 @@
-// Copyright 2017 The Go Authors. All rights reserved.
-// Use of this source code is governed by a BSD-style
-// license that can be found in the LICENSE file.
-
-// Package spanlog provides span and event logger interfaces that are used
-// by the build coordinator infrastructure.
-package spanlog
-
-// SpanLogger is something that has the CreateSpan method, which
-// creates a event spanning some duration which will eventually be
-// logged and visualized.
-type Logger interface {
-	// CreateSpan logs the start of an event.
-	// optText is 0 or 1 strings.
-	CreateSpan(event string, optText ...string) Span
-}
-
-// Span is a handle that can eventually be closed.
-// Typical usage:
-//
-//   sp := sl.CreateSpan("slow_operation")
-//   result, err := doSlowOperation()
-//   sp.Done(err)
-//   // do something with result, err
-type Span interface {
-	// Done marks a span as done.
-	// The err is returned unmodified for convenience at callsites.
-	Done(err error) error
-}
-
-// TODO(quentin): Move loggerFunc and createSpan from coordinator.go to here.
diff --git a/internal/buildgo/benchmarks.go b/internal/buildgo/benchmarks.go
index a14453eb88..ed25472c43 100644
--- a/internal/buildgo/benchmarks.go
+++ b/internal/buildgo/benchmarks.go
@@ -15,9 +15,9 @@ import (
 
 	"golang.org/x/build/buildenv"
 	"golang.org/x/build/buildlet"
-	"golang.org/x/build/cmd/coordinator/spanlog"
 	"golang.org/x/build/dashboard"
 	"golang.org/x/build/internal/sourcecache"
+	"golang.org/x/build/internal/spanlog"
 )
 
 // benchRuns is the number of times to run each benchmark binary
diff --git a/internal/buildgo/buildgo.go b/internal/buildgo/buildgo.go
index 35c89df75d..3862085f8d 100644
--- a/internal/buildgo/buildgo.go
+++ b/internal/buildgo/buildgo.go
@@ -20,9 +20,9 @@ import (
 
 	"golang.org/x/build/buildenv"
 	"golang.org/x/build/buildlet"
-	"golang.org/x/build/cmd/coordinator/spanlog"
 	"golang.org/x/build/dashboard"
 	"golang.org/x/build/internal/sourcecache"
+	"golang.org/x/build/internal/spanlog"
 )
 
 // BuilderRev is a build configuration type and a revision.
diff --git a/internal/sourcecache/source.go b/internal/sourcecache/source.go
index 6c79183e8c..933cd8a291 100644
--- a/internal/sourcecache/source.go
+++ b/internal/sourcecache/source.go
@@ -19,9 +19,9 @@ import (
 	"net/http"
 	"time"
 
-	"golang.org/x/build/cmd/coordinator/spanlog"
 	"golang.org/x/build/internal/lru"
 	"golang.org/x/build/internal/singleflight"
+	"golang.org/x/build/internal/spanlog"
 )
 
 var processStartTime = time.Now()