diff --git a/mlir/lib/IR/BuiltinTypes.cpp b/mlir/lib/IR/BuiltinTypes.cpp
--- a/mlir/lib/IR/BuiltinTypes.cpp
+++ b/mlir/lib/IR/BuiltinTypes.cpp
@@ -214,7 +214,10 @@
   return num;
 }
 
-int64_t ShapedType::getRank() const { return getShape().size(); }
+int64_t ShapedType::getRank() const {
+  assert(hasRank() && "cannot query rank of unranked shaped type");
+  return getShape().size();
+}
 
 bool ShapedType::hasRank() const {
   return !isa<UnrankedMemRefType, UnrankedTensorType>();