1diff --git a/cbackend.cpp b/cbackend.cpp
2index 3552205..9c05824 100644
3--- a/cbackend.cpp
4+++ b/cbackend.cpp
5@@ -1641,7 +1641,7 @@ void CWriter::printConstant(llvm::Constant *CPV, bool Static) {
6 V = Tmp.convertToDouble();
7 }
8
9- if (isnan(V)) {
10+ if (std::isnan(V)) {
11 // The value is NaN
12
13 // FIXME the actual NaN bits should be emitted.
14@@ -1665,7 +1665,7 @@ void CWriter::printConstant(llvm::Constant *CPV, bool Static) {
15 else
16 Out << "LLVM_NAN" << (Val == QuietNaN ? "" : "S") << "(\""
17 << Buffer << "\") /*nan*/ ";
18- } else if (isinf(V)) {
19+ } else if (std::isinf(V)) {
20 // The value is Inf
21 if (V < 0) Out << '-';
22 Out << "LLVM_INF" <<