diff --git a/lib/astutils.cpp b/lib/astutils.cpp
index 5be309bb9e4..96ba644f3d5 100644
--- a/lib/astutils.cpp
+++ b/lib/astutils.cpp
@@ -245,6 +245,12 @@ bool astIsContainer(const Token* tok) {
     return getLibraryContainer(tok) != nullptr && !astIsIterator(tok);
 }
 
+bool astIsNonStringContainer(const Token* tok)
+{
+    const Library::Container* container = getLibraryContainer(tok);
+    return container && !container->stdStringLike && !astIsIterator(tok);
+}
+
 bool astIsContainerView(const Token* tok)
 {
     const Library::Container* container = getLibraryContainer(tok);
diff --git a/lib/astutils.h b/lib/astutils.h
index 10699f8de61..1526d00a7d7 100644
--- a/lib/astutils.h
+++ b/lib/astutils.h
@@ -164,6 +164,7 @@ bool astIsUniqueSmartPointer(const Token* tok);
 bool astIsIterator(const Token *tok);
 
 bool astIsContainer(const Token *tok);
+bool astIsNonStringContainer(const Token *tok);
 
 bool astIsContainerView(const Token* tok);
 bool astIsContainerOwned(const Token* tok);
diff --git a/lib/valueflow.cpp b/lib/valueflow.cpp
index ee8ad0d0d14..61cfc06acaa 100644
--- a/lib/valueflow.cpp
+++ b/lib/valueflow.cpp
@@ -4489,7 +4489,7 @@ static void valueFlowLifetimeFunction(Token *tok, TokenList &tokenlist, ErrorLog
                 tok->next(), tokenlist, errorLogger, settings);
         }
     } else if (memtok && Token::Match(tok->astParent(), ". push_back|push_front|insert|push|assign") &&
-               astIsContainer(memtok)) {
+               astIsNonStringContainer(memtok)) {
         std::vector<const Token *> args = getArguments(tok);
         const std::size_t n = args.size();
         if (n > 1 && Token::typeStr(args[n - 2]) == Token::typeStr(args[n - 1]) &&
diff --git a/test/testautovariables.cpp b/test/testautovariables.cpp
index 666023b5f3c..ef8cd776a2b 100644
--- a/test/testautovariables.cpp
+++ b/test/testautovariables.cpp
@@ -2815,6 +2815,16 @@ class TestAutoVariables : public TestFixture {
               "    return ss;\n"
               "}\n");
         ASSERT_EQUALS("", errout_str());
+
+        check("void f() {\n" // #12568
+              "    std::string str;\n"
+              "    {\n"
+              "        std::unique_ptr<char[]> b(new char[1]{});\n"
+              "        str.assign(b.get());\n"
+              "    }\n"
+              "    std::cerr << str;\n"
+              "}\n");
+        ASSERT_EQUALS("", errout_str());
     }
 
     void danglingLifetimeContainerView()