diff --git a/mlir/lib/Dialect/Linalg/Transforms/ElementwiseOpFusion.cpp b/mlir/lib/Dialect/Linalg/Transforms/ElementwiseOpFusion.cpp
--- a/mlir/lib/Dialect/Linalg/Transforms/ElementwiseOpFusion.cpp
+++ b/mlir/lib/Dialect/Linalg/Transforms/ElementwiseOpFusion.cpp
@@ -318,6 +318,13 @@
       consumer.iterator_types(),
       /*doc=*/nullptr,
       /*library_call=*/nullptr);
+  if (!fusedOp.getShapesToLoopsMap()) {
+    // Fused op has invalid indexing maps. Typically this means something is off
+    // in the input, but going ahead here would result in verification errors.
+    // So cleanup and abort.
+    rewriter.eraseOp(fusedOp);
+    return llvm::None;
+  }
 
   // Construct an AffineMap from consumer loops to producer loops.
   // consumer loop -> tensor index
diff --git a/mlir/test/Dialect/Linalg/fusion-elementwise-ops.mlir b/mlir/test/Dialect/Linalg/fusion-elementwise-ops.mlir
--- a/mlir/test/Dialect/Linalg/fusion-elementwise-ops.mlir
+++ b/mlir/test/Dialect/Linalg/fusion-elementwise-ops.mlir
@@ -945,3 +945,33 @@
   } -> tensor<?xf32>
   return %8 : tensor<?xf32>
 }
+
+// -----
+
+func @illegal_fusion(%arg0 : tensor<5000xi64>, %arg1 : tensor<5000xi32>) -> tensor<5000xi32> {
+  %c1_i32 = arith.constant 1 : i32
+  %0 = linalg.generic {
+        indexing_maps = [affine_map<(d0) -> (d0)>],
+        iterator_types = ["parallel"]}
+        outs(%arg0 : tensor<5000xi64>) {
+        ^bb0(%arg3: i64):  // no predecessors
+          %22 = linalg.index 0 : index
+          %23 = arith.index_cast %22 : index to i64
+          linalg.yield %23 : i64
+        } -> tensor<5000xi64>
+  %1 = linalg.init_tensor [5000] : tensor<5000xi32>
+  %2 = linalg.generic {
+        indexing_maps = [affine_map<(d0, d1) -> (d0)>, affine_map<(d0, d1) -> (d1)>],
+        iterator_types = ["parallel", "parallel"]}
+        ins(%0 : tensor<5000xi64>) outs(%1 : tensor<5000xi32>) {
+        ^bb0(%arg3: i64, %arg5: i32):  // no predecessors
+          %22 = arith.index_cast %arg3 : i64 to index
+          %23 = tensor.extract %arg1[%22] : tensor<5000xi32>
+          linalg.yield %23 : i32
+        } -> tensor<5000xi32>
+  return %2 : tensor<5000xi32>
+}
+// CHECK-LABEL: func @illegal_fusion(
+//       CHECK:   %[[PRODUCER:.+]] = linalg.generic
+//       CHECK:    linalg.generic
+//   CHECK-SAME:       ins(%[[PRODUCER]]