diff --git a/CHANGES b/CHANGES
index c4d2d26a68..44d8cf4c93 100644
--- a/CHANGES
+++ b/CHANGES
@@ -1,4 +1,8 @@
 
+2.6-279 | 2019-05-13 20:02:59 -0700
+
+  * GH-365: improve un-indexable type error message (Jon Siwek, Corelight)
+
 2.6-277 | 2019-05-08 12:42:18 -0700
 
   * Allow tuning Broker log batching via scripts (Jon Siwek, Corelight)
diff --git a/VERSION b/VERSION
index 64298b5057..1268552eaf 100644
--- a/VERSION
+++ b/VERSION
@@ -1 +1 @@
-2.6-277
+2.6-279
diff --git a/src/Expr.cc b/src/Expr.cc
index e6cb9937c4..efbd96f04f 100644
--- a/src/Expr.cc
+++ b/src/Expr.cc
@@ -2917,7 +2917,12 @@ IndexExpr::IndexExpr(Expr* arg_op1, ListExpr* arg_op2, bool is_slice)
 
 	int match_type = op1->Type()->MatchesIndex(arg_op2);
 	if ( match_type == DOES_NOT_MATCH_INDEX )
-		SetError("not an index type");
+		{
+		std::string error_msg =
+		    fmt("expression with type '%s' is not a type that can be indexed",
+		        type_name(op1->Type()->Tag()));
+		SetError(error_msg.data());
+		}
 
 	else if ( ! op1->Type()->YieldType() )
 		{