diff --git a/src/Desc.h b/src/Desc.h
index b2f4bb56fa..de09e37ad8 100644
--- a/src/Desc.h
+++ b/src/Desc.h
@@ -9,7 +9,7 @@
 
 #include "zeek/IntrusivePtr.h"
 #include "zeek/ZeekString.h" // for byte_vec
-#include "zeek/util.h"       // for zeek_int_t
+#include "zeek/util-types.h"
 
 namespace zeek {
 
diff --git a/src/Event.h b/src/Event.h
index 82804ca58d..7fd5db7fcf 100644
--- a/src/Event.h
+++ b/src/Event.h
@@ -9,7 +9,7 @@
 #include "zeek/ZeekArgs.h"
 #include "zeek/analyzer/Analyzer.h"
 #include "zeek/iosource/IOSource.h"
-#include "zeek/util.h"
+#include "zeek/util-types.h"
 
 namespace zeek {
 
diff --git a/src/Frag.h b/src/Frag.h
index e705b4304c..62ba30ea3f 100644
--- a/src/Frag.h
+++ b/src/Frag.h
@@ -8,7 +8,7 @@
 #include "zeek/IPAddr.h"
 #include "zeek/Reassem.h"
 #include "zeek/Timer.h"
-#include "zeek/util.h" // for zeek_uint_t
+#include "zeek/util-types.h"
 
 namespace zeek {
 
diff --git a/src/Hash.h b/src/Hash.h
index aaee8d3df3..7d72957c03 100644
--- a/src/Hash.h
+++ b/src/Hash.h
@@ -22,7 +22,7 @@
 #include <unistd.h>
 #include <cstdlib>
 
-#include "zeek/util.h" // for zeek_int_t
+#include "zeek/util-types.h" // for zeek_int_t
 
 // to allow md5_hmac_bif access to the hmac seed
 #include "zeek/ZeekArgs.h"
diff --git a/src/Overflow.h b/src/Overflow.h
index 0eba5e9237..2ba86b6fc5 100644
--- a/src/Overflow.h
+++ b/src/Overflow.h
@@ -2,9 +2,14 @@
 
 #pragma once
 
-#include "zeek/Type.h"
+#include "zeek/util-types.h"
 
-namespace zeek::detail {
+namespace zeek {
+
+class Type;
+class Val;
+
+namespace detail {
 
 inline bool double_to_count_would_overflow(double v) { return v < 0.0 || v > static_cast<double>(UINT64_MAX); }
 
@@ -18,4 +23,5 @@ inline bool count_to_int_would_overflow(zeek_uint_t v) { return v > INT64_MAX; }
 
 extern bool would_overflow(const zeek::Type* from_type, const zeek::Type* to_type, const Val* val);
 
-} // namespace zeek::detail
+} // namespace detail
+} // namespace zeek
diff --git a/src/UID.h b/src/UID.h
index 35e49bc5fa..aeccc03684 100644
--- a/src/UID.h
+++ b/src/UID.h
@@ -5,7 +5,7 @@
 #include <cstring>
 #include <string>
 
-#include "zeek/util.h" // for zeek_int_t
+#include "zeek/util-types.h"
 
 namespace zeek {
 
diff --git a/src/analyzer/Component.h b/src/analyzer/Component.h
index 9f5e645e1b..f9ca753c88 100644
--- a/src/analyzer/Component.h
+++ b/src/analyzer/Component.h
@@ -4,7 +4,6 @@
 
 #include "zeek/Tag.h"
 #include "zeek/plugin/Component.h"
-#include "zeek/util.h"
 
 namespace zeek {
 
diff --git a/src/binpac_zeek-lib.pac b/src/binpac_zeek-lib.pac
index 2b32edccd9..0e91f31438 100644
--- a/src/binpac_zeek-lib.pac
+++ b/src/binpac_zeek-lib.pac
@@ -1,7 +1,7 @@
 %extern{
 #include "zeek/3rdparty/ConvertUTF.h"
 #include "zeek/binpac_zeek.h"
-#include "zeek/util.h"
+#include "zeek/util-types.h"
 #include "zeek/Reporter.h"
 #include "zeek/Val.h"
 #include "zeek/RunState.h"
diff --git a/src/digest.h b/src/digest.h
index e846257451..07ee1c776b 100644
--- a/src/digest.h
+++ b/src/digest.h
@@ -10,7 +10,7 @@
 #include <cstdint>
 #include <cstdio>
 
-#include "zeek/util.h"
+#include "zeek/util.h" // for util::bytetohex
 
 // Required buffer size for an MD5 digest.
 #define ZEEK_MD5_DIGEST_LENGTH 16
diff --git a/src/iosource/BPF_Program.h b/src/iosource/BPF_Program.h
index 3e562921f2..68370a040c 100644
--- a/src/iosource/BPF_Program.h
+++ b/src/iosource/BPF_Program.h
@@ -5,7 +5,7 @@
 #include <cstdint>
 #include <string>
 
-#include "zeek/util.h"
+#include "zeek/util-types.h"
 
 extern "C" {
 #include <pcap.h>
diff --git a/src/packet_analysis/Component.h b/src/packet_analysis/Component.h
index 1d176939cb..0e9ec2a0e5 100644
--- a/src/packet_analysis/Component.h
+++ b/src/packet_analysis/Component.h
@@ -6,7 +6,6 @@
 
 #include "zeek/Tag.h"
 #include "zeek/plugin/Component.h"
-#include "zeek/util.h"
 
 namespace zeek::packet_analysis {
 
diff --git a/src/script_opt/ZAM/Frame.h b/src/script_opt/ZAM/Frame.h
index a2ea9e0a7b..35fd0edc21 100644
--- a/src/script_opt/ZAM/Frame.h
+++ b/src/script_opt/ZAM/Frame.h
@@ -8,7 +8,7 @@
 
 #include "zeek/Attr.h"
 #include "zeek/ID.h"
-#include "zeek/util.h"
+#include "zeek/util-types.h"
 
 namespace zeek::detail {
 
diff --git a/src/script_opt/ZAM/Support.h b/src/script_opt/ZAM/Support.h
index 2edec3de4a..b3b1236c78 100644
--- a/src/script_opt/ZAM/Support.h
+++ b/src/script_opt/ZAM/Support.h
@@ -9,11 +9,13 @@
 
 #pragma once
 
+#include <memory>
+#include <string>
 #include <vector>
 
 #include "zeek/IntrusivePtr.h"
 #include "zeek/script_opt/ZAM/Profile.h"
-#include "zeek/util.h"
+#include "zeek/util-types.h"
 
 namespace zeek {
 
diff --git a/src/telemetry/MetricFamily.h b/src/telemetry/MetricFamily.h
index e10ac608e0..aa2c8da339 100644
--- a/src/telemetry/MetricFamily.h
+++ b/src/telemetry/MetricFamily.h
@@ -6,7 +6,7 @@
 #include <vector>
 
 #include "zeek/Span.h"
-#include "zeek/util.h"
+#include "zeek/util-types.h"
 
 namespace zeek::telemetry {