diff --git a/sys/kern/sys_generic.c b/sys/kern/sys_generic.c
--- a/sys/kern/sys_generic.c
+++ b/sys/kern/sys_generic.c
@@ -1048,15 +1048,35 @@
 		    &td->td_oldsigmask, 0);
 		if (error != 0)
 			return (error);
-		td->td_pflags |= TDP_OLDMASK;
-		/*
-		 * Make sure that ast() is called on return to
-		 * usermode and TDP_OLDMASK is cleared, restoring old
-		 * sigmask.
-		 */
-		ast_sched(td, TDA_SIGSUSPEND);
 	}
 	error = kern_select(td, nd, in, ou, ex, tvp, abi_nfdbits);
+	if (uset != NULL) {
+		if (error == EINTR) {
+			/*
+			 * Make sure that ast() is called on return to
+			 * usermode and TDP_OLDMASK is cleared, restoring old
+			 * sigmask.
+			 */
+			td->td_pflags |= TDP_OLDMASK;
+			ast_sched(td, TDA_SIGSUSPEND);
+		} else {
+			int serror __diagused;
+
+			/* *select(2) should never restart. */
+			MPASS(error != ERESTART);
+
+			/*
+			 * Restore the signal mask before we return if we didn't
+			 * get interrupted in sleep.  The caller is likely not
+			 * expecting a signal to hit that it can't detect by
+			 * checking for EINTR.
+			 */
+			serror = kern_sigprocmask(td, SIG_SETMASK,
+			    &td->td_oldsigmask, NULL, 0);
+			MPASS(serror == 0);
+		}
+	}
+
 	return (error);
 }
 
@@ -1527,13 +1547,6 @@
 		    &td->td_oldsigmask, 0);
 		if (error)
 			return (error);
-		td->td_pflags |= TDP_OLDMASK;
-		/*
-		 * Make sure that ast() is called on return to
-		 * usermode and TDP_OLDMASK is cleared, restoring old
-		 * sigmask.
-		 */
-		ast_sched(td, TDA_SIGSUSPEND);
 	}
 
 	seltdinit(td);
@@ -1556,6 +1569,31 @@
 		error = EINTR;
 	if (error == EWOULDBLOCK)
 		error = 0;
+
+	if (uset != NULL) {
+		if (error == EINTR) {
+			/*
+			 * Make sure that ast() is called on return to
+			 * usermode and TDP_OLDMASK is cleared, restoring old
+			 * sigmask.
+			 */
+			td->td_pflags |= TDP_OLDMASK;
+			ast_sched(td, TDA_SIGSUSPEND);
+		} else {
+			int serror __diagused;
+
+			/*
+			 * Restore the signal mask before we return if we didn't
+			 * get interrupted in sleep.  The caller is likely not
+			 * expecting a signal to hit that it can't detect by
+			 * checking for EINTR.
+			 */
+			serror = kern_sigprocmask(td, SIG_SETMASK,
+			    &td->td_oldsigmask, NULL, 0);
+			MPASS(serror == 0);
+		}
+	}
+
 	return (error);
 }