Index: uspace/lib/math/generic/trunc.c
===================================================================
--- uspace/lib/math/generic/trunc.c	(revision 1ab853969f4ab4bd3b894a43444959889f64873d)
+++ uspace/lib/math/generic/trunc.c	(revision 5a42886138d4aab0bf370134954892eb9896554a)
@@ -68,5 +68,5 @@
 	} else {
 		/* Truncate irrelevant fraction bits */
-		val.parts.fraction &= UINT64_C(0x000fffffffffffff) >> exp;
+		val.parts.fraction &= ~(UINT64_C(0x000fffffffffffff) >> exp);
 	}