1 files changed, 3 insertions, 2 deletions
diff --git a/src/math/atan.c b/src/math/atan.c
index 5a1d33e6..63b0ab25 100644
--- a/src/math/atan.c
+++ b/src/math/atan.c
@@ -77,8 +77,9 @@ double atan(double x)
 	}
 	if (ix < 0x3fdc0000) {    /* |x| < 0.4375 */
 		if (ix < 0x3e400000) {  /* |x| < 2^-27 */
-			/* raise inexact if x!=0 */
-			FORCE_EVAL(x + 0x1p120f);
+			if (ix < 0x00100000)
+				/* raise underflow for subnormal x */
+				FORCE_EVAL((float)x);
 			return x;
 		}
 		id = -1;