diff --git a/mlir/lib/IR/AffineExpr.cpp b/mlir/lib/IR/AffineExpr.cpp
--- a/mlir/lib/IR/AffineExpr.cpp
+++ b/mlir/lib/IR/AffineExpr.cpp
@@ -833,7 +833,8 @@
   // Note, this may not be valid if we ever allow negative modulus constants
   if (lBin && lBin.getKind() == AffineExprKind::Mod) {
     auto intermediate = lBin.getRHS().dyn_cast<AffineConstantExpr>();
-    if (mod(intermediate.getValue(), rhsConst.getValue()) == 0) {
+    if (intermediate &&
+        mod(intermediate.getValue(), rhsConst.getValue()) == 0) {
       return lBin.getLHS() % rhsConst.getValue();
     }
   }