diff --git a/tests/by-util/test_expr.rs b/tests/by-util/test_expr.rs
index 1064ef525..b70c60fb3 100644
--- a/tests/by-util/test_expr.rs
+++ b/tests/by-util/test_expr.rs
@@ -138,6 +138,11 @@ fn test_or() {
         .args(&["0", "|", "10", "/", "5"])
         .succeeds()
         .stdout_only("2\n");
+
+    new_ucmd!()
+        .args(&["12", "|", "9a", "+", "1"])
+        .succeeds()
+        .stdout_only("12\n");
 }
 
 #[test]
@@ -275,3 +280,23 @@ fn test_invalid_substr() {
         .code_is(1)
         .stdout_only("\n");
 }
+
+#[test]
+fn test_escape() {
+    new_ucmd!().args(&["+", "1"]).succeeds().stdout_only("1\n");
+
+    new_ucmd!()
+        .args(&["1", "+", "+", "1"])
+        .succeeds()
+        .stdout_only("2\n");
+
+    new_ucmd!()
+        .args(&["2", "*", "+", "3"])
+        .succeeds()
+        .stdout_only("6\n");
+
+    new_ucmd!()
+        .args(&["(", "1", ")", "+", "1"])
+        .succeeds()
+        .stdout_only("2\n");
+}