diff --git a/src/workerd/api/BUILD.bazel b/src/workerd/api/BUILD.bazel
index 3c31ec6b4e2..771df5cd803 100644
--- a/src/workerd/api/BUILD.bazel
+++ b/src/workerd/api/BUILD.bazel
@@ -8,6 +8,9 @@ filegroup(
     srcs = glob(
         ["**/*.c++"],
         exclude = [
+            # TODO(cleanup): Continue shrinking the io target: Create independent targets for
+            # analytics-engine, kv, urlpattern and streams/compression, which either do not depend
+            # on io or do not have io depending on them.
             "**/*test*.c++",
             "data-url.c++",
             "encoding.c++",
diff --git a/src/workerd/api/analytics-engine.c++ b/src/workerd/api/analytics-engine.c++
index 49bd5433379..6c6ed66bb4f 100644
--- a/src/workerd/api/analytics-engine.c++
+++ b/src/workerd/api/analytics-engine.c++
@@ -4,6 +4,7 @@
 
 #include "analytics-engine.h"
 
+#include <workerd/api/analytics-engine.capnp.h>
 #include <workerd/io/io-context.h>
 
 namespace workerd::api {
diff --git a/src/workerd/api/analytics-engine.h b/src/workerd/api/analytics-engine.h
index d2e16443ee9..64d9c9b9a83 100644
--- a/src/workerd/api/analytics-engine.h
+++ b/src/workerd/api/analytics-engine.h
@@ -5,7 +5,6 @@
 #pragma once
 
 #include <workerd/api/analytics-engine-impl.h>
-#include <workerd/api/analytics-engine.capnp.h>
 #include <workerd/api/util.h>
 #include <workerd/io/io-util.h>
 #include <workerd/jsg/jsg.h>
diff --git a/src/workerd/api/global-scope.c++ b/src/workerd/api/global-scope.c++
index cfee9034790..5ca1869aab2 100644
--- a/src/workerd/api/global-scope.c++
+++ b/src/workerd/api/global-scope.c++
@@ -15,6 +15,7 @@
 #include <workerd/api/system-streams.h>
 #include <workerd/api/trace.h>
 #include <workerd/api/util.h>
+#include <workerd/io/compatibility-date.h>
 #include <workerd/io/features.h>
 #include <workerd/io/io-context.h>
 #include <workerd/jsg/async-context.h>
diff --git a/src/workerd/io/BUILD.bazel b/src/workerd/io/BUILD.bazel
index ca87f5e474d..04032baafd7 100644
--- a/src/workerd/io/BUILD.bazel
+++ b/src/workerd/io/BUILD.bazel
@@ -57,7 +57,6 @@ wd_cc_library(
     srcs = [
         "compatibility-date.c++",
         "features.c++",
-        "frankenvalue.c++",
         "hibernation-manager.c++",
         "io-context.c++",
         "io-own.c++",
@@ -70,7 +69,6 @@ wd_cc_library(
     hdrs = [
         "compatibility-date.h",
         "features.h",
-        "frankenvalue.h",
         "hibernation-manager.h",
         "io-channels.h",
         "io-context.h",
@@ -100,7 +98,7 @@ wd_cc_library(
         ":actor-id",
         ":actor-storage_capnp",
         ":cdp_capnp",
-        ":frankenvalue_capnp",
+        ":frankenvalue",
         ":io-gate",
         ":io-helpers",
         ":limit-enforcer",
@@ -159,6 +157,18 @@ wd_cc_library(
     ],
 )
 
+wd_cc_library(
+    name = "frankenvalue",
+    srcs = ["frankenvalue.c++"],
+    hdrs = ["frankenvalue.h"],
+    visibility = ["//visibility:public"],
+    deps = [
+        ":frankenvalue_capnp",
+        "//src/workerd/jsg",
+        "@capnp-cpp//src/capnp:capnpc",
+    ],
+)
+
 wd_cc_library(
     name = "trace",
     srcs = ["trace.c++"],
@@ -354,6 +364,6 @@ kj_test(
 kj_test(
     src = "frankenvalue-test.c++",
     deps = [
-        ":io",
+        ":frankenvalue",
     ],
 )
diff --git a/src/workerd/io/features.h b/src/workerd/io/features.h
index 2a00be1c4b8..28e0fb62809 100644
--- a/src/workerd/io/features.h
+++ b/src/workerd/io/features.h
@@ -5,7 +5,6 @@
 #pragma once
 
 #include <workerd/io/compatibility-date.capnp.h>
-#include <workerd/io/compatibility-date.h>
 #include <workerd/jsg/jsg.h>
 
 namespace workerd {
diff --git a/src/workerd/io/io-channels.h b/src/workerd/io/io-channels.h
index 52e3cbdf891..f08993e88c0 100644
--- a/src/workerd/io/io-channels.h
+++ b/src/workerd/io/io-channels.h
@@ -8,6 +8,7 @@
 #include <workerd/io/io-util.h>
 #include <workerd/io/trace.h>
 
+#include <capnp/capability.h>  // for Capability
 #include <kj/debug.h>
 #include <kj/string.h>
 
diff --git a/src/workerd/io/io-gate.h b/src/workerd/io/io-gate.h
index 29b4fe85b3d..3f3b1f5ae54 100644
--- a/src/workerd/io/io-gate.h
+++ b/src/workerd/io/io-gate.h
@@ -24,8 +24,6 @@
 #include <kj/list.h>
 #include <kj/one-of.h>
 
-#include <type_traits>
-
 namespace workerd {
 
 using kj::uint;
diff --git a/src/workerd/io/io-own.c++ b/src/workerd/io/io-own.c++
index 925def361f2..e2f9fe14f18 100644
--- a/src/workerd/io/io-own.c++
+++ b/src/workerd/io/io-own.c++
@@ -2,6 +2,8 @@
 
 #include "io-context.h"
 
+#include <workerd/jsg/util.h>
+
 namespace workerd {
 
 #ifdef KJ_DEBUG
diff --git a/src/workerd/io/io-own.h b/src/workerd/io/io-own.h
index 4786104b747..cde31d5f5ae 100644
--- a/src/workerd/io/io-own.h
+++ b/src/workerd/io/io-own.h
@@ -1,6 +1,5 @@
 #pragma once
 
-#include <workerd/jsg/util.h>
 #include <workerd/util/weak-refs.h>
 
 #include <kj/async-io.h>
@@ -13,6 +12,9 @@
 #include <typeinfo>
 
 namespace workerd {
+namespace jsg {
+class Lock;
+}
 
 class IoContext;
 
diff --git a/src/workerd/io/worker-entrypoint.h b/src/workerd/io/worker-entrypoint.h
index f6ad7ccc388..b1517196e9e 100644
--- a/src/workerd/io/worker-entrypoint.h
+++ b/src/workerd/io/worker-entrypoint.h
@@ -4,7 +4,7 @@
 
 #pragma once
 
-#include <workerd/io/frankenvalue.capnp.h>
+#include <workerd/io/frankenvalue.h>
 #include <workerd/io/worker.h>
 
 namespace workerd {
diff --git a/src/workerd/server/alarm-scheduler.c++ b/src/workerd/server/alarm-scheduler.c++
index 3c3c0b09b43..c22d436d4c3 100644
--- a/src/workerd/server/alarm-scheduler.c++
+++ b/src/workerd/server/alarm-scheduler.c++
@@ -4,6 +4,8 @@
 
 #include "alarm-scheduler.h"
 
+#include <cmath>
+
 namespace workerd::server {
 
 int AlarmScheduler::maxJitterMsForDelay(kj::Duration delay) {
diff --git a/src/workerd/util/sqlite.h b/src/workerd/util/sqlite.h
index 06e74a5f97e..7d0e3db98fd 100644
--- a/src/workerd/util/sqlite.h
+++ b/src/workerd/util/sqlite.h
@@ -5,8 +5,10 @@
 #pragma once
 
 #include <kj/filesystem.h>
+#include <kj/function.h>
 #include <kj/list.h>
 #include <kj/one-of.h>
+#include <kj/string.h>
 
 #include <utility>