diff --git a/src/librustc/middle/trans/common.rs b/src/librustc/middle/trans/common.rs
index 743e85e458e..9f81aa00193 100644
--- a/src/librustc/middle/trans/common.rs
+++ b/src/librustc/middle/trans/common.rs
@@ -307,8 +307,8 @@ impl FunctionContext {
 }
 
 pub fn warn_not_to_commit(ccx: &mut CrateContext, msg: &str) {
-    if !ccx.do_not_commit_warning_issued {
-        ccx.do_not_commit_warning_issued = true;
+    if !ccx.do_not_commit_warning_issued.get() {
+        ccx.do_not_commit_warning_issued.set(true);
         ccx.sess.warn(msg.to_str() + " -- do not commit like this!");
     }
 }
diff --git a/src/librustc/middle/trans/context.rs b/src/librustc/middle/trans/context.rs
index 9857ff37b94..7d0eb736195 100644
--- a/src/librustc/middle/trans/context.rs
+++ b/src/librustc/middle/trans/context.rs
@@ -112,7 +112,7 @@ pub struct CrateContext {
      // is not emitted by LLVM's GC pass when no functions use GC.
      uses_gc: bool,
      dbg_cx: Option<debuginfo::CrateDebugContext>,
-     do_not_commit_warning_issued: bool
+     do_not_commit_warning_issued: Cell<bool>,
 }
 
 impl CrateContext {
@@ -232,7 +232,7 @@ impl CrateContext {
                   crate_map_name: crate_map_name,
                   uses_gc: false,
                   dbg_cx: dbg_cx,
-                  do_not_commit_warning_issued: false
+                  do_not_commit_warning_issued: Cell::new(false),
             }
         }
     }