diff --git a/CHANGES b/CHANGES
index 04b025c23b3..7013e2a9312 100644
--- a/CHANGES
+++ b/CHANGES
@@ -1,4 +1,9 @@
 
+2.5-840 | 2018-08-13 17:40:06 -0500
+
+  * Fix SumStats::observe key normalization logic
+    (reported by Jim Mellander and fixed by Jon Siwek, Corelight)
+
 2.5-839 | 2018-08-13 10:51:43 -0500
 
   * Make options redef-able by default. (Johanna Amann, Corelight)
diff --git a/VERSION b/VERSION
index 7960a61cb9e..446a694de2f 100644
--- a/VERSION
+++ b/VERSION
@@ -1 +1 @@
-2.5-839
+2.5-840
diff --git a/scripts/base/frameworks/sumstats/main.bro b/scripts/base/frameworks/sumstats/main.bro
index f704dbcdd27..69a853fd5aa 100644
--- a/scripts/base/frameworks/sumstats/main.bro
+++ b/scripts/base/frameworks/sumstats/main.bro
@@ -399,7 +399,7 @@ function create(ss: SumStat)
 	schedule ss$epoch { SumStats::finish_epoch(ss) };
 	}
 
-function observe(id: string, key: Key, obs: Observation)
+function observe(id: string, orig_key: Key, obs: Observation)
 	{
 	if ( id !in reducer_store )
 		return;
@@ -407,8 +407,7 @@ function observe(id: string, key: Key, obs: Observation)
 	# Try to add the data to all of the defined reducers.
 	for ( r in reducer_store[id] )
 		{
-		if ( r?$normalize_key )
-			key = r$normalize_key(copy(key));
+		local key = r?$normalize_key ? r$normalize_key(copy(orig_key)) : orig_key;
 
 		# If this reducer has a predicate, run the predicate
 		# and skip this key if the predicate return false.