diff --git a/lib/checkuninitvar.cpp b/lib/checkuninitvar.cpp
index 14d9cf18d..adb70a508 100644
--- a/lib/checkuninitvar.cpp
+++ b/lib/checkuninitvar.cpp
@@ -1072,7 +1072,7 @@ void CheckUninitVar::checkScope(const Scope* scope)
 
         bool stdtype = _tokenizer->isC();
         const Token* tok = i->typeStartToken();
-        for (; tok->str() != ";" && tok->str() != "<"; tok = tok->next()) {
+        for (; tok && tok->str() != ";" && tok->str() != "<"; tok = tok->next()) {
             if (tok->isStandardType())
                 stdtype = true;
         }
diff --git a/test/testuninitvar.cpp b/test/testuninitvar.cpp
index f15234b05..36646a2cf 100644
--- a/test/testuninitvar.cpp
+++ b/test/testuninitvar.cpp
@@ -2126,6 +2126,8 @@ private:
                         "}\n");
         ASSERT_EQUALS("", errout.str());
 
+        checkUninitVar2(">{ x while (y) z int = }"); // #4175 : don't crash
+
         // try
         checkUninitVar2("void f() {\n"
                         "    int i, *p = &i;\n"