diff --git a/lib/tokenize.cpp b/lib/tokenize.cpp
index 796f61470..9ac0a9d80 100644
--- a/lib/tokenize.cpp
+++ b/lib/tokenize.cpp
@@ -2516,7 +2516,7 @@ void Tokenizer::setVarId()
             }
         } else if (tok->str() == "}") {
             // parse anonymous unions as part of the current scope
-            if (!(Token::simpleMatch(tok, "} ;") && Token::simpleMatch(tok->link()->previous(), "union {"))) {
+            if (!(Token::simpleMatch(tok, "} ;") && tok->link() && Token::simpleMatch(tok->link()->previous(), "union {"))) {
                 // Set variable ids in class declaration..
                 if (!isC() && !executableScope.top() && tok->link()) {
                     setVarIdClassDeclaration(tok->link(),
diff --git a/test/testtokenize.cpp b/test/testtokenize.cpp
index e266792c8..4bfebd9f1 100644
--- a/test/testtokenize.cpp
+++ b/test/testtokenize.cpp
@@ -67,6 +67,7 @@ private:
         TEST_CASE(tokenize30);  // #5356 (segmentation fault upon invalid code)
         TEST_CASE(tokenize31);  // #3503 (Wrong handling of member function taking function pointer as argument)
         TEST_CASE(tokenize32);  // #5884 (fsanitize=undefined: left shift of negative value -10000 in lib/templatesimplifier.cpp:852:46)
+        TEST_CASE(tokenize33);  // #5780 Various crashes on valid template code
 
         // don't freak out when the syntax is wrong
         TEST_CASE(wrong_syntax1);
@@ -905,6 +906,15 @@ private:
         ASSERT_EQUALS(code, tokenizeAndStringify(code));
     }
 
+    // ##5780 Various crashes on valid template code in Tokenizer::setVarId()
+    void tokenize33() {
+        const char * code = "template<typename T, typename A = Alloc<T>> struct vector {};\n"
+            "void z() {\n"
+            "    vector<int> VI;\n"
+            "}\n";
+        ASSERT_EQUALS(code, tokenizeAndStringify(code));
+    }
+
     void wrong_syntax1() {
         {
             const char code[] ="TR(kvmpio, PROTO(int rw), ARGS(rw), TP_(aa->rw;))";