diff --git a/src/librustc/session/mod.rs b/src/librustc/session/mod.rs
index 67c39bcca81f..560b2a0ed6a8 100644
--- a/src/librustc/session/mod.rs
+++ b/src/librustc/session/mod.rs
@@ -64,12 +64,21 @@ pub struct Session {
 
 impl Session {
     pub fn span_fatal(&self, sp: Span, msg: &str) -> ! {
+        if self.opts.treat_err_as_bug {
+            self.span_bug(sp, msg);
+        }
         self.diagnostic().span_fatal(sp, msg)
     }
     pub fn span_fatal_with_code(&self, sp: Span, msg: &str, code: &str) -> ! {
+        if self.opts.treat_err_as_bug {
+            self.span_bug(sp, msg);
+        }
         self.diagnostic().span_fatal_with_code(sp, msg, code)
     }
     pub fn fatal(&self, msg: &str) -> ! {
+        if self.opts.treat_err_as_bug {
+            self.bug(msg);
+        }
         self.diagnostic().handler().fatal(msg)
     }
     pub fn span_err(&self, sp: Span, msg: &str) {