diff --git a/src/math_special.cpp b/src/math_special.cpp
index d778e1e1adc5c9df576733a82df2e397aaee3be7..4b9197f0fc150e7452351b3eee441872641a5457 100644
--- a/src/math_special.cpp
+++ b/src/math_special.cpp
@@ -537,10 +537,8 @@ double MathSpecial::exp2_x86(double x)
 
 double MathSpecial::fm_exp(double x)
 {
-#if defined(__BYTE_ORDER__)
-#if __BYTE_ORDER__ == __ORDER_LITTLE_ENDIAN__
+#if defined(__BYTE_ORDER__) && (__BYTE_ORDER__ == __ORDER_LITTLE_ENDIAN__)
     return exp2_x86(FM_DOUBLE_LOG2OFE * x);
-#endif
 #else
     return ::exp(x);
 #endif