diff --git a/include/tvm/topi/einsum.h b/include/tvm/topi/einsum.h
index 9cfa09826f..b5756e1200 100644
--- a/include/tvm/topi/einsum.h
+++ b/include/tvm/topi/einsum.h
@@ -96,7 +96,7 @@ struct EinsumEquation {
   // The output subscript of the Einsum equation.
   Subscript output;
   // The number of outputs.
-  int num_outputs = 0;
+  size_t num_outputs = 0;
 
   /*!
    * \brief Set output subscript of the Einsum equation, and ensure that
diff --git a/src/topi/einsum.cc b/src/topi/einsum.cc
index 0bf5d4f1a3..1fc1cd8ff6 100644
--- a/src/topi/einsum.cc
+++ b/src/topi/einsum.cc
@@ -257,7 +257,7 @@ class EinsumBuilder {
           result = result * operands[i];
         }
       }
-      for (int i = 0; i < equation_.num_outputs; ++i) {
+      for (size_t i = 0; i < equation_.num_outputs; ++i) {
         results.push_back(result);
       }
     }