diff --git a/synapse/util/metrics.py b/synapse/util/metrics.py
index e1f374807..0b944d3e6 100644
--- a/synapse/util/metrics.py
+++ b/synapse/util/metrics.py
@@ -84,7 +84,7 @@ class Measure(object):
 
         if context != self.start_context:
             logger.warn(
-                "Context have unexpectedly changed from '%s' to '%s'. (%r)",
+                "Context has unexpectedly changed from '%s' to '%s'. (%r)",
                 context, self.start_context, self.name
             )
             return