1 files changed, 5 insertions, 0 deletions
diff --git a/src/util.h b/src/util.h
index e697b92..30544ca 100644
--- a/src/util.h
+++ b/src/util.h
@@ -12,6 +12,9 @@
 // See the License for the specific language governing permissions and
 // limitations under the License.
 
+#ifndef NINJA_UTIL_H_
+#define NINJA_UTIL_H_
+
 // Dump a backtrace to stderr.
 // |skip_frames| is how many frames to skip;
 // DumpBacktrace implicitly skips itself already.
@@ -22,3 +25,5 @@ void Fatal(const char* msg, ...);
 
 // Log an error message.
 void Error(const char* msg, ...);
+
+#endif // NINJA_UTIL_H_