diff --git a/tests/by-util/test_dd.rs b/tests/by-util/test_dd.rs
index e1e55054a..64ca7603b 100644
--- a/tests/by-util/test_dd.rs
+++ b/tests/by-util/test_dd.rs
@@ -1658,13 +1658,14 @@ fn test_reading_partial_blocks_from_fifo() {
     // Start different processes to write to the FIFO, with a small
     // pause in between.
     let mut writer_command = Command::new("sh");
-    writer_command
+    let _ = writer_command
         .args([
             "-c",
             &format!("(printf \"ab\"; sleep 0.1; printf \"cd\") > {fifoname}"),
         ])
         .spawn()
-        .unwrap();
+        .unwrap()
+        .wait();
 
     let output = child.wait_with_output().unwrap();
     assert_eq!(output.stdout, b"abcd");
@@ -1701,13 +1702,14 @@ fn test_reading_partial_blocks_from_fifo_unbuffered() {
     // Start different processes to write to the FIFO, with a small
     // pause in between.
     let mut writer_command = Command::new("sh");
-    writer_command
+    let _ = writer_command
         .args([
             "-c",
             &format!("(printf \"ab\"; sleep 0.1; printf \"cd\") > {fifoname}"),
         ])
         .spawn()
-        .unwrap();
+        .unwrap()
+        .wait();
 
     let output = child.wait_with_output().unwrap();
     assert_eq!(output.stdout, b"abcd");
diff --git a/tests/by-util/test_env.rs b/tests/by-util/test_env.rs
index 8c5b43b2d..a1b13e020 100644
--- a/tests/by-util/test_env.rs
+++ b/tests/by-util/test_env.rs
@@ -36,13 +36,14 @@ impl Target {
         Self { child }
     }
     fn send_signal(&mut self, signal: Signal) {
-        Command::new("kill")
+        let _ = Command::new("kill")
             .args(&[
                 format!("-{}", signal as i32),
                 format!("{}", self.child.id()),
             ])
             .spawn()
-            .expect("failed to send signal");
+            .expect("failed to send signal")
+            .wait();
         self.child.delay(100);
     }
     fn is_alive(&mut self) -> bool {