diff --git a/renderdoc/replay/replay_driver.cpp b/renderdoc/replay/replay_driver.cpp
index fd19176e3..a8603fb75 100644
--- a/renderdoc/replay/replay_driver.cpp
+++ b/renderdoc/replay/replay_driver.cpp
@@ -482,7 +482,7 @@ static void StandardFillCBufferVariables(ResourceId shader, const rdcarray<Shade
     }
 
     size_t outIdx = outvars.size();
-    outvars.resize(outvars.size() + 1);
+    outvars.push_back({});
 
     {
       const VarType type = invars[v].type.descriptor.type;