diff --git a/lib/valueflow.cpp b/lib/valueflow.cpp
index a3881cb22..c463a8307 100644
--- a/lib/valueflow.cpp
+++ b/lib/valueflow.cpp
@@ -6295,8 +6295,9 @@ static void valueFlowContainerSize(TokenList *tokenlist, SymbolDatabase* symbold
                     value.valueType = ValueFlow::Value::ValueType::CONTAINER_SIZE;
                     value.setKnown();
                     valueFlowContainerForward(tok->next(), tok->variable(), value, tokenlist);
-                } else if (action == Library::Container::Action::RESIZE && tok->tokAt(4)->hasKnownIntValue()) {
-                    ValueFlow::Value value(tok->tokAt(4)->values().front());
+                } else if (action == Library::Container::Action::RESIZE && tok->tokAt(3)->astOperand2() &&
+                           tok->tokAt(3)->astOperand2()->hasKnownIntValue()) {
+                    ValueFlow::Value value(tok->tokAt(3)->astOperand2()->values().front());
                     value.valueType = ValueFlow::Value::ValueType::CONTAINER_SIZE;
                     value.setKnown();
                     valueFlowContainerForward(tok->next(), tok->variable(), value, tokenlist);
diff --git a/test/testvalueflow.cpp b/test/testvalueflow.cpp
index 638c24e80..61b397a71 100644
--- a/test/testvalueflow.cpp
+++ b/test/testvalueflow.cpp
@@ -5079,6 +5079,16 @@ private:
         ASSERT_EQUALS("",
                       isPossibleContainerSizeValue(tokenValues(code, "x . front", ValueFlow::Value::ValueType::CONTAINER_SIZE), 0));
 
+        code = "int f() {\n"
+               "    const size_t len = 6;\n"
+               "    std::vector<char> v;\n"
+               "    v.resize(1 + len);\n"
+               "    return v.front();\n"
+               "}\n";
+        ASSERT_EQUALS(
+            "",
+            isKnownContainerSizeValue(tokenValues(code, "v . front", ValueFlow::Value::ValueType::CONTAINER_SIZE), 7));
+
         code = "void f(std::string str) {\n"
                "    if (str == \"123\") {\n"
                "        bool x = (str == \"\");\n"