diff --git a/src/evalfunc.c b/src/evalfunc.c
index e7683fc..e69f293 100644
--- a/src/evalfunc.c
+++ b/src/evalfunc.c
@@ -8400,7 +8400,7 @@
 	return;
     }
     if (argvars[1].v_type != VAR_UNKNOWN)
-	retList = (int)tv_get_number_chk(&argvars[1], &error);
+	retList = (int)tv_get_bool_chk(&argvars[1], &error);
     if (error)
 	return;