diff --git a/src/libsyntax/error_codes.rs b/src/libsyntax/error_codes.rs
index 941df5ea57087..7cf722299ad96 100644
--- a/src/libsyntax/error_codes.rs
+++ b/src/libsyntax/error_codes.rs
@@ -518,6 +518,24 @@ undefined number of parameters to a given function (like `printf` in C). The
 equivalent in Rust would be to use macros directly.
 "##,
 
+E0744: r##"
+A raw string isn't terminated.
+
+Erroneous code example:
+
+```compile_fail,E0744
+let dolphins = r##"Dolphins!"#; // error!
+```
+
+To terminate a raw string, you have to have the same number of `#` at the end
+than at the beginning. Example:
+
+```
+let dolphins = r#"Dolphins!"#; // one `#` at the beginning, one at the end so
+                               // all good!
+```
+"##,
+
 ;
 
     E0539, // incorrect meta item
diff --git a/src/libsyntax/parse/lexer/mod.rs b/src/libsyntax/parse/lexer/mod.rs
index e2a7ea28b9b59..4bf39d59e5907 100644
--- a/src/libsyntax/parse/lexer/mod.rs
+++ b/src/libsyntax/parse/lexer/mod.rs
@@ -501,8 +501,10 @@ impl<'a> StringReader<'a> {
     }
 
     fn report_unterminated_raw_string(&self, start: BytePos, n_hashes: usize) -> ! {
-        let mut err = self.struct_span_fatal(
-            start, start,
+        let mut err = struct_span_fatal!(
+            self.sess.span_diagnostic,
+            self.mk_sp(start, start),
+            E0744,
             "unterminated raw string",
         );
         err.span_label(
diff --git a/src/test/ui/parser/raw-byte-string-eof.stderr b/src/test/ui/parser/raw-byte-string-eof.stderr
index 65fa89f2a81ac..16a953606306b 100644
--- a/src/test/ui/parser/raw-byte-string-eof.stderr
+++ b/src/test/ui/parser/raw-byte-string-eof.stderr
@@ -1,4 +1,4 @@
-error: unterminated raw string
+error[E0744]: unterminated raw string
   --> $DIR/raw-byte-string-eof.rs:2:5
    |
 LL |     br##"a"#;
@@ -8,3 +8,4 @@ LL |     br##"a"#;
 
 error: aborting due to previous error
 
+For more information about this error, try `rustc --explain E0744`.
diff --git a/src/test/ui/parser/raw-str-unterminated.stderr b/src/test/ui/parser/raw-str-unterminated.stderr
index 67792eb91e5ca..d3c7cc18b63a0 100644
--- a/src/test/ui/parser/raw-str-unterminated.stderr
+++ b/src/test/ui/parser/raw-str-unterminated.stderr
@@ -1,4 +1,4 @@
-error: unterminated raw string
+error[E0744]: unterminated raw string
   --> $DIR/raw-str-unterminated.rs:2:5
    |
 LL |     r#" string literal goes on
@@ -8,3 +8,4 @@ LL |     r#" string literal goes on
 
 error: aborting due to previous error
 
+For more information about this error, try `rustc --explain E0744`.
diff --git a/src/test/ui/parser/raw/raw_string.stderr b/src/test/ui/parser/raw/raw_string.stderr
index 5572511881d57..e192d07909e48 100644
--- a/src/test/ui/parser/raw/raw_string.stderr
+++ b/src/test/ui/parser/raw/raw_string.stderr
@@ -1,4 +1,4 @@
-error: unterminated raw string
+error[E0744]: unterminated raw string
   --> $DIR/raw_string.rs:2:13
    |
 LL |     let x = r##"lol"#;
@@ -8,3 +8,4 @@ LL |     let x = r##"lol"#;
 
 error: aborting due to previous error
 
+For more information about this error, try `rustc --explain E0744`.