diff --git a/src/libcore/fmt/builders.rs b/src/libcore/fmt/builders.rs
index b594c886b64f5..60b9eeb1283cd 100644
--- a/src/libcore/fmt/builders.rs
+++ b/src/libcore/fmt/builders.rs
@@ -8,7 +8,7 @@
 // option. This file may not be copied, modified, or distributed
 // except according to those terms.
 
-use fmt::{self, FlagV1};
+use fmt;
 
 struct PadAdapter<'a, 'b: 'a> {
     fmt: &'a mut fmt::Formatter<'b>,
@@ -140,7 +140,7 @@ impl<'a, 'b: 'a> DebugStruct<'a, 'b> {
     }
 
     fn is_pretty(&self) -> bool {
-        self.fmt.flags() & (1 << (FlagV1::Alternate as usize)) != 0
+        self.fmt.alternate()
     }
 }
 
@@ -233,7 +233,7 @@ impl<'a, 'b: 'a> DebugTuple<'a, 'b> {
     }
 
     fn is_pretty(&self) -> bool {
-        self.fmt.flags() & (1 << (FlagV1::Alternate as usize)) != 0
+        self.fmt.alternate()
     }
 }
 
@@ -277,7 +277,7 @@ impl<'a, 'b: 'a> DebugInner<'a, 'b> {
     }
 
     fn is_pretty(&self) -> bool {
-        self.fmt.flags() & (1 << (FlagV1::Alternate as usize)) != 0
+        self.fmt.alternate()
     }
 }
 
@@ -519,6 +519,6 @@ impl<'a, 'b: 'a> DebugMap<'a, 'b> {
     }
 
     fn is_pretty(&self) -> bool {
-        self.fmt.flags() & (1 << (FlagV1::Alternate as usize)) != 0
+        self.fmt.alternate()
     }
 }
diff --git a/src/libcore/fmt/mod.rs b/src/libcore/fmt/mod.rs
index 6c251b9eb0924..32f1142069e22 100644
--- a/src/libcore/fmt/mod.rs
+++ b/src/libcore/fmt/mod.rs
@@ -322,7 +322,6 @@ impl<'a> ArgumentV1<'a> {
 
 // flags available in the v1 format of format_args
 #[derive(Copy, Clone)]
-#[allow(dead_code)] // SignMinus isn't currently used
 enum FlagV1 { SignPlus, SignMinus, Alternate, SignAwareZeroPad, }
 
 impl<'a> Arguments<'a> {
@@ -1276,7 +1275,7 @@ impl<'a> Formatter<'a> {
         write(self.buf, fmt)
     }
 
-    /// Flags for formatting (packed version of rt::Flag)
+    /// Flags for formatting
     #[stable(feature = "rust1", since = "1.0.0")]
     pub fn flags(&self) -> u32 { self.flags }