diff --git a/Cargo.toml b/Cargo.toml
index 0e7179094..530e2139b 100644
--- a/Cargo.toml
+++ b/Cargo.toml
@@ -56,7 +56,7 @@ generic = [
   "od",
   "paste",
   "printenv",
-  "ptx",	# skip_on_stable
+  "ptx",
   "pwd",
   "readlink",
   "realpath",
diff --git a/src/ptx/ptx.rs b/src/ptx/ptx.rs
index c12a2d5ad..1ccf3f2eb 100644
--- a/src/ptx/ptx.rs
+++ b/src/ptx/ptx.rs
@@ -334,9 +334,9 @@ fn trim_idx(s: &[char], beg: usize, end: usize) -> (usize, usize) {
 
 fn get_output_chunks(all_before: &str, keyword: &str, all_after: &str,
                     config: &Config) -> (String, String, String, String) {
-    assert_eq!(all_before.trim().to_owned(), *all_before);
-    assert_eq!(keyword.trim().to_owned(), *keyword);
-    assert_eq!(all_after.trim().to_owned(), *all_after);
+    assert_eq!(all_before.trim(), all_before);
+    assert_eq!(keyword.trim(), keyword);
+    assert_eq!(all_after.trim(), all_after);
     let mut head = String::new();
     let mut before = String::new();
     let mut after = String::new();