diff --git a/src/BifReturnVal.cc b/src/BifReturnVal.cc
new file mode 100644
index 0000000000..8a8444161b
--- /dev/null
+++ b/src/BifReturnVal.cc
@@ -0,0 +1,11 @@
+// See the file "COPYING" in the main distribution directory for copyright.
+
+#include "BifReturnVal.h"
+#include "Val.h"
+
+BifReturnVal::BifReturnVal(std::nullptr_t) noexcept
+	{}
+
+BifReturnVal::BifReturnVal(Val* v) noexcept
+	: rval(AdoptRef{}, v)
+	{}
diff --git a/src/BifReturnVal.h b/src/BifReturnVal.h
new file mode 100644
index 0000000000..2f6293cdf8
--- /dev/null
+++ b/src/BifReturnVal.h
@@ -0,0 +1,28 @@
+// See the file "COPYING" in the main distribution directory for copyright.
+
+#pragma once
+
+#include "IntrusivePtr.h"
+
+class Val;
+
+/**
+ * A simple wrapper class to use for the return value of BIFs so that
+ * they may return either a Val* or IntrusivePtr<Val> (the former could
+ * potentially be deprecated).
+ */
+class BifReturnVal {
+public:
+
+	template <typename T>
+	BifReturnVal(IntrusivePtr<T> v) noexcept
+		: rval(AdoptRef{}, v.release())
+		{ }
+
+	BifReturnVal(std::nullptr_t) noexcept;
+
+	[[deprecated("Remove in v4.1.  Return an IntrusivePtr instead.")]]
+	BifReturnVal(Val* v) noexcept;
+
+	IntrusivePtr<Val> rval;
+};
diff --git a/src/CMakeLists.txt b/src/CMakeLists.txt
index e8ccafb544..d19badde10 100644
--- a/src/CMakeLists.txt
+++ b/src/CMakeLists.txt
@@ -218,6 +218,7 @@ set(MAIN_SRCS
     Anon.cc
     Attr.cc
     Base64.cc
+    BifReturnVal.cc
     Brofiler.cc
     BroString.cc
     CCL.cc
diff --git a/src/CompHash.cc b/src/CompHash.cc
index e8d2c5a681..5243e4241e 100644
--- a/src/CompHash.cc
+++ b/src/CompHash.cc
@@ -2,6 +2,7 @@
 
 #include "zeek-config.h"
 
+#include <cstring>
 #include <vector>
 #include <map>
 
diff --git a/src/EventHandler.cc b/src/EventHandler.cc
index 68673801d1..890bda3a4d 100644
--- a/src/EventHandler.cc
+++ b/src/EventHandler.cc
@@ -44,6 +44,12 @@ const IntrusivePtr<FuncType>& EventHandler::GetType(bool check_export)
 	return type;
 	}
 
+void EventHandler::SetFunc(IntrusivePtr<Func> f)
+	{ local = std::move(f); }
+
+void EventHandler::SetLocalHandler(Func* f)
+	{ SetFunc({NewRef{}, f}); }
+
 void EventHandler::Call(zeek::Args* vl, bool no_remote)
 	{
 #ifdef PROFILE_BRO_FUNCTIONS
diff --git a/src/EventHandler.h b/src/EventHandler.h
index c2a053cac8..056165271b 100644
--- a/src/EventHandler.h
+++ b/src/EventHandler.h
@@ -5,11 +5,12 @@
 #include "BroList.h"
 #include "ZeekArgs.h"
 #include "Type.h"
-#include "Func.h"
 
 #include <unordered_set>
 #include <string>
 
+class Func;
+
 class EventHandler {
 public:
 	explicit EventHandler(std::string name);
@@ -28,12 +29,10 @@ public:
 	FuncType* FType(bool check_export = true)
 		{ return GetType().get(); }
 
-	void SetFunc(IntrusivePtr<Func> f)
-		{ local = std::move(f); }
+	void SetFunc(IntrusivePtr<Func> f);
 
 	[[deprecated("Remove in v4.1.  Use SetFunc().")]]
-	void SetLocalHandler(Func* f)
-		{ SetFunc({NewRef{}, f}); }
+	void SetLocalHandler(Func* f);
 
 	void AutoPublish(std::string topic)
 		{
diff --git a/src/EventRegistry.cc b/src/EventRegistry.cc
index 7cf05a7042..29c06dc26f 100644
--- a/src/EventRegistry.cc
+++ b/src/EventRegistry.cc
@@ -1,5 +1,6 @@
 #include "EventRegistry.h"
 #include "EventHandler.h"
+#include "Func.h"
 #include "RE.h"
 #include "Reporter.h"
 
diff --git a/src/Func.cc b/src/Func.cc
index f0cb8e693a..38ec25b137 100644
--- a/src/Func.cc
+++ b/src/Func.cc
@@ -892,10 +892,3 @@ function_ingredients::function_ingredients(IntrusivePtr<Scope> scope, IntrusiveP
 	priority = (attrs ? get_func_priority(*attrs) : 0);
 	this->body = std::move(body);
 	}
-
-BifReturnVal::BifReturnVal(std::nullptr_t) noexcept
-	{ }
-
-BifReturnVal::BifReturnVal(Val* v) noexcept
-	: rval(AdoptRef{}, v)
-	{ }
diff --git a/src/Func.h b/src/Func.h
index 5b2ee5eebc..c8a284e3bd 100644
--- a/src/Func.h
+++ b/src/Func.h
@@ -9,15 +9,13 @@
 #include <tuple>
 #include <type_traits>
 
-#include <broker/data.hh>
-#include <broker/expected.hh>
-
 #include "BroList.h"
 #include "Obj.h"
 #include "IntrusivePtr.h"
 #include "Type.h" /* for function_flavor */
 #include "TraverseTypes.h"
 #include "ZeekArgs.h"
+#include "BifReturnVal.h"
 
 class Val;
 class ListExpr;
@@ -28,6 +26,16 @@ class ID;
 class CallExpr;
 class Scope;
 
+namespace caf {
+template <class> class expected;
+}
+
+namespace broker {
+class data;
+using vector = std::vector<data>;
+using caf::expected;
+}
+
 class Func : public BroObj {
 public:
 	static inline const IntrusivePtr<Func> nil;
@@ -205,27 +213,6 @@ private:
 	bool weak_closure_ref = false;
 };
 
-/**
- * A simple wrapper class to use for the return value of BIFs so that
- * they may return either a Val* or IntrusivePtr<Val> (the former could
- * potentially be deprecated).
- */
-class BifReturnVal {
-public:
-
-	template <typename T>
-	BifReturnVal(IntrusivePtr<T> v) noexcept
-		: rval(AdoptRef{}, v.release())
-		{ }
-
-	BifReturnVal(std::nullptr_t) noexcept;
-
-	[[deprecated("Remove in v4.1.  Return an IntrusivePtr instead.")]]
-	BifReturnVal(Val* v) noexcept;
-
-	IntrusivePtr<Val> rval;
-};
-
 using built_in_func = BifReturnVal (*)(Frame* frame, const zeek::Args* args);
 
 class BuiltinFunc final : public Func {
diff --git a/src/bro-bif.h b/src/bro-bif.h
index b72d676312..7af9c1a6d3 100644
--- a/src/bro-bif.h
+++ b/src/bro-bif.h
@@ -7,3 +7,4 @@
 #include "Reporter.h"
 #include "ID.h"
 #include "EventRegistry.h"
+#include "BifReturnVal.h"
diff --git a/src/file_analysis/analyzer/x509/X509.cc b/src/file_analysis/analyzer/x509/X509.cc
index 9da3adc349..dc48b0a6d3 100644
--- a/src/file_analysis/analyzer/x509/X509.cc
+++ b/src/file_analysis/analyzer/x509/X509.cc
@@ -12,6 +12,8 @@
 #include "file_analysis/Manager.h"
 
 #include <broker/error.hh>
+#include <broker/expected.hh>
+#include <broker/data.hh>
 
 #include <openssl/x509.h>
 #include <openssl/x509v3.h>