diff --git a/lib/valueflow.cpp b/lib/valueflow.cpp
index e2b6e6fc8..0e9cda6ae 100644
--- a/lib/valueflow.cpp
+++ b/lib/valueflow.cpp
@@ -6850,12 +6850,12 @@ static bool isContainerSizeChanged(const Token* tok, const Settings* settings, i
         case Library::Container::Action::CHANGE:
         case Library::Container::Action::INSERT:
         case Library::Container::Action::ERASE:
-        case Library::Container::Action::CHANGE_INTERNAL:
             return true;
         case Library::Container::Action::NO_ACTION: // might be unknown action
             return yield == Library::Container::Yield::NO_YIELD;
         case Library::Container::Action::FIND:
         case Library::Container::Action::CHANGE_CONTENT:
+        case Library::Container::Action::CHANGE_INTERNAL:
             break;
         }
     }
diff --git a/test/testvalueflow.cpp b/test/testvalueflow.cpp
index 68e07372a..c6bfca4e6 100644
--- a/test/testvalueflow.cpp
+++ b/test/testvalueflow.cpp
@@ -5818,6 +5818,15 @@ private:
                "    return v;\n"
                "}\n";
         ASSERT_EQUALS(true, tokenValues(code, "v [ 0 ] != 0 ) { }", ValueFlow::Value::ValueType::CONTAINER_SIZE).empty());
+
+        code = "std::vector<int> f() {\n"
+               "    std::vector<int> v;\n"
+               "    v.reserve(1);\n"
+               "    v[1] = 42;\n"
+               "    return v;\n"
+               "}\n";
+        ASSERT_EQUALS(
+            "", isKnownContainerSizeValue(tokenValues(code, "v [", ValueFlow::Value::ValueType::CONTAINER_SIZE), 0));
     }
 
     void valueFlowDynamicBufferSize() {