diff --git a/kernel/log.cc b/kernel/log.cc
index 5390cabc0..8ba20d64d 100644
--- a/kernel/log.cc
+++ b/kernel/log.cc
@@ -386,13 +386,10 @@ void log_formatted_error(std::string str)
 	log_error_with_prefix("ERROR: ", std::move(str));
 }
 
-void log_cmd_error(const char *format, ...)
+void log_formatted_cmd_error(std::string str)
 {
-	va_list ap;
-	va_start(ap, format);
-
 	if (log_cmd_error_throw) {
-		log_last_error = vstringf(format, ap);
+		log_last_error = str;
 
 		// Make sure the error message gets through any selective silencing
 		// of log output
@@ -402,7 +399,7 @@ void log_cmd_error(const char *format, ...)
 			pop_errfile = true;
 		}
 
-		log("ERROR: %s", log_last_error.c_str());
+		log("ERROR: %s", log_last_error);
 		log_flush();
 
 		if (pop_errfile)
@@ -411,7 +408,7 @@ void log_cmd_error(const char *format, ...)
 		throw log_cmd_error_exception();
 	}
 
-	log_formatted_error(vstringf(format, ap));
+	log_formatted_error(str);
 }
 
 void log_spacer()
diff --git a/kernel/log.h b/kernel/log.h
index 036a2aa4d..6bfc0b421 100644
--- a/kernel/log.h
+++ b/kernel/log.h
@@ -124,8 +124,6 @@ extern int log_debug_suppressed;
 void set_verific_logging(void (*cb)(int msg_type, const char *message_id, const char* file_path, unsigned int left_line, unsigned int left_col, unsigned int right_line, unsigned int right_col, const char *msg));
 extern void (*log_verific_callback)(int msg_type, const char *message_id, const char* file_path, unsigned int left_line, unsigned int left_col, unsigned int right_line, unsigned int right_col, const char *msg);
 
-[[noreturn]] void log_cmd_error(const char *format, ...) YS_ATTRIBUTE(format(printf, 1, 2));
-
 #ifndef NDEBUG
 static inline bool ys_debug(int n = 0) { if (log_force_debug) return true; log_debug_suppressed += n; return false; }
 #else
@@ -194,6 +192,13 @@ template <typename... Args>
 	log_formatted_file_error(filename, lineno, fmt.format(args...));
 }
 
+[[noreturn]] void log_formatted_cmd_error(std::string str);
+template <typename... Args>
+[[noreturn]] void log_cmd_error(FmtString<TypeIdentity<Args>...> fmt, Args... args)
+{
+	log_formatted_cmd_error(fmt.format(args...));
+}
+
 static inline void log_suppressed() {
 	if (log_debug_suppressed && !log_make_debug) {
 		log("<suppressed ~%d debug messages>\n", log_debug_suppressed);