diff --git a/proto/invoke.options b/proto/invoke.options
index 90f381e..b6d2f12 100644
--- a/proto/invoke.options
+++ b/proto/invoke.options
@@ -8,3 +8,4 @@ fd_exec_test.InstrContext.data type:FT_POINTER
 
 fd_exec_test.InstrEffects.modified_accounts type:FT_POINTER
 fd_exec_test.InstrEffects.return_data type:FT_POINTER
+fd_exec_test.InstrEffects.log type:FT_POINTER
diff --git a/proto/invoke.proto b/proto/invoke.proto
index 1ea2f38..e72f74c 100644
--- a/proto/invoke.proto
+++ b/proto/invoke.proto
@@ -55,6 +55,9 @@ message InstrEffects {
 
   // Instruction return data.
   bytes return_data = 5;
+
+  // Any logs that were emitted during execution.
+  bytes log = 6;
 }
 
 // An instruction processing test fixture.