diff --git a/src/liballoc/string.rs b/src/liballoc/string.rs
index 2cb81029f95e..c1ef1c2f96c7 100644
--- a/src/liballoc/string.rs
+++ b/src/liballoc/string.rs
@@ -2009,9 +2009,9 @@ impl From<Box<str>> for String {
 }
 
 #[stable(feature = "box_from_str", since = "1.18.0")]
-impl Into<Box<str>> for String {
-    fn into(self) -> Box<str> {
-        self.into_boxed_str()
+impl From<String> for Box<str> {
+    fn from(s: String) -> Box<str> {
+        s.into_boxed_str()
     }
 }
 
diff --git a/src/libstd/ffi/c_str.rs b/src/libstd/ffi/c_str.rs
index 1a91417ca0e9..1586e0a4ddbd 100644
--- a/src/libstd/ffi/c_str.rs
+++ b/src/libstd/ffi/c_str.rs
@@ -586,10 +586,10 @@ impl From<Box<CStr>> for CString {
 }
 
 #[stable(feature = "box_from_c_string", since = "1.18.0")]
-impl Into<Box<CStr>> for CString {
+impl From<CString> for Box<CStr> {
     #[inline]
-    fn into(self) -> Box<CStr> {
-        self.into_boxed_c_str()
+    fn from(s: CString) -> Box<CStr> {
+        s.into_boxed_c_str()
     }
 }
 
diff --git a/src/libstd/ffi/os_str.rs b/src/libstd/ffi/os_str.rs
index f54d79c201f4..3815f9866818 100644
--- a/src/libstd/ffi/os_str.rs
+++ b/src/libstd/ffi/os_str.rs
@@ -543,9 +543,9 @@ impl From<Box<OsStr>> for OsString {
 }
 
 #[stable(feature = "box_from_os_string", since = "1.18.0")]
-impl Into<Box<OsStr>> for OsString {
-    fn into(self) -> Box<OsStr> {
-        self.into_boxed_os_str()
+impl From<OsString> for Box<OsStr> {
+    fn from(s: OsString) -> Box<OsStr> {
+        s.into_boxed_os_str()
     }
 }
 
diff --git a/src/libstd/path.rs b/src/libstd/path.rs
index 42a54ed6d754..e9bf7b33b8e4 100644
--- a/src/libstd/path.rs
+++ b/src/libstd/path.rs
@@ -1349,9 +1349,9 @@ impl From<Box<Path>> for PathBuf {
 }
 
 #[stable(feature = "box_from_path_buf", since = "1.18.0")]
-impl Into<Box<Path>> for PathBuf {
-    fn into(self) -> Box<Path> {
-        self.into_boxed_path()
+impl From<PathBuf> for Box<Path> {
+    fn from(p: PathBuf) -> Box<Path> {
+        p.into_boxed_path()
     }
 }