diff --git a/NEWS b/NEWS
index d3777ae5f7..8bdffeda9b 100644
--- a/NEWS
+++ b/NEWS
@@ -15,6 +15,12 @@ Changed Functionality
 Removed Functionality
 ---------------------
 
+- The fmt() function which takes a va_list argument is replaced, use
+  the new vfmt() function for equivalent functionality.  The former is
+  deprecated because overloading it with the variadic fmt() function
+  can cause the unintended overload to be chosen depending on how the
+  platform implements va_list.
+
 Deprecated Functionality
 ------------------------
 
diff --git a/src/broker/Manager.cc b/src/broker/Manager.cc
index eae0ce723f..bb5d3a6af3 100644
--- a/src/broker/Manager.cc
+++ b/src/broker/Manager.cc
@@ -625,7 +625,7 @@ void Manager::Error(const char* format, ...)
 	{
 	va_list args;
 	va_start(args, format);
-	auto msg = fmt(format, args);
+	auto msg = vfmt(format, args);
 	va_end(args);
 
 	if ( script_scope )
diff --git a/src/supervisor/Supervisor.cc b/src/supervisor/Supervisor.cc
index a1dd2a21d4..685b0707e7 100644
--- a/src/supervisor/Supervisor.cc
+++ b/src/supervisor/Supervisor.cc
@@ -724,7 +724,7 @@ void Stem::ReportStatus(const Supervisor::Node& node) const
 
 void Stem::Log(std::string_view type, const char* format, va_list args) const
 	{
-	auto raw_msg = fmt(format, args);
+	auto raw_msg = vfmt(format, args);
 
 	if ( getenv("ZEEK_DEBUG_STEM_STDERR") )
 		{
diff --git a/src/util.cc b/src/util.cc
index 6429e1481d..e75e79882d 100644
--- a/src/util.cc
+++ b/src/util.cc
@@ -817,7 +817,7 @@ const char* fmt_bytes(const char* data, int len)
 	return buf;
 	}
 
-const char* fmt(const char* format, va_list al)
+const char* vfmt(const char* format, va_list al)
 	{
 	static char* buf = 0;
 	static unsigned int buf_len = 1024;
@@ -848,7 +848,7 @@ const char* fmt(const char* format, ...)
 	{
 	va_list al;
 	va_start(al, format);
-	auto rval = fmt(format, al);
+	auto rval = vfmt(format, al);
 	va_end(al);
 	return rval;
 	}
diff --git a/src/util.h b/src/util.h
index cb5e1fc2eb..ae2f0fc2d4 100644
--- a/src/util.h
+++ b/src/util.h
@@ -188,7 +188,7 @@ extern std::string strtolower(const std::string& s);
 extern const char* fmt_bytes(const char* data, int len);
 
 // Note: returns a pointer into a shared buffer.
-extern const char* fmt(const char* format, va_list args);
+extern const char* vfmt(const char* format, va_list args);
 // Note: returns a pointer into a shared buffer.
 extern const char* fmt(const char* format, ...)
 	__attribute__((format (printf, 1, 2)));