Index: src/cmd/basecomputer.cpp
--- src/cmd/basecomputer.cpp.orig
+++ src/cmd/basecomputer.cpp
@@ -4704,7 +4704,7 @@ bool BaseComputer::showPlayerInfo(const EventCommandId
 //does not work with negative numbers!!
 void prettyPrintFloat(char *buffer, float f, int digitsBefore, int digitsAfter, int bufferLen) {
     int bufferPos = 0;
-    if (!FINITE(f) || ISNAN(f)) {
+    if (!FINITE(f) || std::isnan(f)) {
         buffer[0] = 'n';
         buffer[1] = '/';
         buffer[2] = 'a';
