diff --git a/clang/lib/StaticAnalyzer/Checkers/IteratorRangeChecker.cpp b/clang/lib/StaticAnalyzer/Checkers/IteratorRangeChecker.cpp
--- a/clang/lib/StaticAnalyzer/Checkers/IteratorRangeChecker.cpp
+++ b/clang/lib/StaticAnalyzer/Checkers/IteratorRangeChecker.cpp
@@ -228,7 +228,7 @@
     Value = State->getRawSVal(*ValAsLoc);
   }
 
-  if (Value.isUnknown())
+  if (Value.isUnknownOrUndef())
     return;
 
   // Incremention or decremention by 0 is never a bug.
diff --git a/clang/test/Analysis/iterator-range.cpp b/clang/test/Analysis/iterator-range.cpp
--- a/clang/test/Analysis/iterator-range.cpp
+++ b/clang/test/Analysis/iterator-range.cpp
@@ -939,3 +939,10 @@
   auto i0 = c.begin(), i1 = c.end();
   ptrdiff_t len = i1 - i0; // no-crash
 }
+
+int uninit_var(int n) {
+  int uninit; // expected-note{{'uninit' declared without an initial value}}
+  return n - uninit; // no-crash
+  // expected-warning@-1 {{The right operand of '-' is a garbage value}}
+  // expected-note@-2 {{The right operand of '-' is a garbage value}}
+}