diff --git a/src/dawn/native/metal/ShaderModuleMTL.mm b/src/dawn/native/metal/ShaderModuleMTL.mm
index 350b5d0..c841d00 100644
--- a/src/dawn/native/metal/ShaderModuleMTL.mm
+++ b/src/dawn/native/metal/ShaderModuleMTL.mm
@@ -38,6 +38,7 @@
 #define MSL_COMPILATION_REQUEST_MEMBERS(X)                                                  \
     X(SingleShaderStage, stage)                                                             \
     X(const tint::Program*, inputProgram)                                                   \
+    X(tint::writer::ArrayLengthFromUniformOptions, arrayLengthFromUniform)                  \
     X(tint::transform::BindingRemapper::BindingPoints, bindingPoints)                       \
     X(tint::transform::MultiplanarExternalTexture::BindingsMap, externalTextureBindings)    \
     X(OptionalVertexPullingTransformConfig, vertexPullingTransformConfig)                   \
@@ -114,6 +115,9 @@
     using BindingPoint = tint::writer::BindingPoint;
     BindingRemapper::BindingPoints bindingPoints;
 
+    tint::writer::ArrayLengthFromUniformOptions arrayLengthFromUniform;
+    arrayLengthFromUniform.ubo_binding = {0, kBufferLengthBufferSlot};
+
     for (BindGroupIndex group : IterateBitSet(layout->GetBindGroupLayoutsMask())) {
         const BindGroupLayoutBase::BindingMap& bindingMap =
             layout->GetBindGroupLayout(group)->GetBindingMap();
@@ -133,6 +137,16 @@
             if (srcBindingPoint != dstBindingPoint) {
                 bindingPoints.emplace(srcBindingPoint, dstBindingPoint);
             }
+
+            // Use the ShaderIndex as the indices for the buffer size lookups in the array length
+            // uniform transform. This is used to compute the size of variable length arrays in
+            // storage buffers.
+            if (bindingInfo.buffer.type == wgpu::BufferBindingType::Storage ||
+                bindingInfo.buffer.type == wgpu::BufferBindingType::ReadOnlyStorage ||
+                bindingInfo.buffer.type == kInternalStorageBufferBinding) {
+                arrayLengthFromUniform.bindpoint_to_size_index.emplace(dstBindingPoint,
+                                                                       dstBindingPoint.binding);
+            }
         }
     }
 
@@ -154,6 +168,11 @@
             if (srcBindingPoint != dstBindingPoint) {
                 bindingPoints.emplace(srcBindingPoint, dstBindingPoint);
             }
+
+            // Use the ShaderIndex as the indices for the buffer size lookups in the array
+            // length uniform transform.
+            arrayLengthFromUniform.bindpoint_to_size_index.emplace(dstBindingPoint,
+                                                                   dstBindingPoint.binding);
         }
     }
 
@@ -177,6 +196,7 @@
     req.isRobustnessEnabled = device->IsRobustnessEnabled();
     req.disableSymbolRenaming = device->IsToggleEnabled(Toggle::DisableSymbolRenaming);
     req.tracePlatform = UnsafeUnkeyedValue(device->GetPlatform());
+    req.arrayLengthFromUniform = std::move(arrayLengthFromUniform);
 
     const CombinedLimits& limits = device->GetLimits();
     req.limits = LimitsForCompilationRequest::Create(limits.v1);
@@ -264,6 +284,8 @@
             options.fixed_sample_mask = r.sampleMask;
             options.disable_workgroup_init = r.disableWorkgroupInit;
             options.emit_vertex_point_size = r.emitVertexPointSize;
+            options.array_length_from_uniform = r.arrayLengthFromUniform;
+
             TRACE_EVENT0(r.tracePlatform.UnsafeGetValue(), General, "tint::writer::msl::Generate");
             auto result = tint::writer::msl::Generate(&program, options);
             DAWN_INVALID_IF(!result.success, "An error occured while generating MSL: %s.",
diff --git a/src/tint/cmd/main.cc b/src/tint/cmd/main.cc
index 898f0ac..45982f2 100644
--- a/src/tint/cmd/main.cc
+++ b/src/tint/cmd/main.cc
@@ -660,6 +660,11 @@
     gen_options.disable_workgroup_init = options.disable_workgroup_init;
     gen_options.external_texture_options.bindings_map =
         tint::cmd::GenerateExternalTextureBindings(input_program);
+    gen_options.array_length_from_uniform.ubo_binding = tint::writer::BindingPoint{0, 30};
+    gen_options.array_length_from_uniform.bindpoint_to_size_index.emplace(
+        tint::writer::BindingPoint{0, 0}, 0);
+    gen_options.array_length_from_uniform.bindpoint_to_size_index.emplace(
+        tint::writer::BindingPoint{0, 1}, 1);
     auto result = tint::writer::msl::Generate(input_program, gen_options);
     if (!result.success) {
         tint::cmd::PrintWGSL(std::cerr, *program);
diff --git a/src/tint/writer/msl/generator_impl.cc b/src/tint/writer/msl/generator_impl.cc
index 268736f..ae49d5d 100644
--- a/src/tint/writer/msl/generator_impl.cc
+++ b/src/tint/writer/msl/generator_impl.cc
@@ -173,29 +173,6 @@
     // ExpandCompoundAssignment must come before BuiltinPolyfill
     manager.Add<transform::ExpandCompoundAssignment>();
 
-    // Build the config for the internal ArrayLengthFromUniform transform.
-    auto& array_length_from_uniform = options.array_length_from_uniform;
-    transform::ArrayLengthFromUniform::Config array_length_from_uniform_cfg(
-        array_length_from_uniform.ubo_binding);
-    if (!array_length_from_uniform.bindpoint_to_size_index.empty()) {
-        // If |array_length_from_uniform| bindings are provided, use that config.
-        array_length_from_uniform_cfg.bindpoint_to_size_index =
-            array_length_from_uniform.bindpoint_to_size_index;
-    } else {
-        // If the binding map is empty, use the deprecated |buffer_size_ubo_index|
-        // and automatically choose indices using the binding numbers.
-        array_length_from_uniform_cfg = transform::ArrayLengthFromUniform::Config(
-            sem::BindingPoint{0, options.buffer_size_ubo_index});
-        // Use the SSBO binding numbers as the indices for the buffer size lookups.
-        for (auto* var : in->AST().GlobalVariables()) {
-            auto* global = in->Sem().Get<sem::GlobalVariable>(var);
-            if (global && global->AddressSpace() == builtin::AddressSpace::kStorage) {
-                array_length_from_uniform_cfg.bindpoint_to_size_index.emplace(
-                    global->BindingPoint(), global->BindingPoint().binding);
-            }
-        }
-    }
-
     // Build the configs for the internal CanonicalizeEntryPointIO transform.
     auto entry_point_io_cfg = transform::CanonicalizeEntryPointIO::Config(
         transform::CanonicalizeEntryPointIO::ShaderStyle::kMsl, options.fixed_sample_mask,
@@ -210,6 +187,7 @@
     if (!options.disable_robustness) {
         // Robustness must come after PromoteSideEffectsToDecl
         // Robustness must come before BuiltinPolyfill and CanonicalizeEntryPointIO
+        // Robustness must come before ArrayLengthFromUniform
         manager.Add<transform::Robustness>();
     }
 
@@ -260,10 +238,16 @@
     // ArrayLengthFromUniform must come after SimplifyPointers, as
     // it assumes that the form of the array length argument is &var.array.
     manager.Add<transform::ArrayLengthFromUniform>();
+
+    transform::ArrayLengthFromUniform::Config array_length_cfg(
+        std::move(options.array_length_from_uniform.ubo_binding));
+    array_length_cfg.bindpoint_to_size_index =
+        std::move(options.array_length_from_uniform.bindpoint_to_size_index);
+    data.Add<transform::ArrayLengthFromUniform::Config>(array_length_cfg);
+
     // PackedVec3 must come after ExpandCompoundAssignment.
     manager.Add<transform::PackedVec3>();
     manager.Add<transform::ModuleScopeVarToEntryPointParam>();
-    data.Add<transform::ArrayLengthFromUniform::Config>(std::move(array_length_from_uniform_cfg));
     data.Add<transform::CanonicalizeEntryPointIO::Config>(std::move(entry_point_io_cfg));
     auto out = manager.Run(in, data);
 
diff --git a/src/tint/writer/msl/generator_impl_sanitizer_test.cc b/src/tint/writer/msl/generator_impl_sanitizer_test.cc
index f72e0e9..c75fe92 100644
--- a/src/tint/writer/msl/generator_impl_sanitizer_test.cc
+++ b/src/tint/writer/msl/generator_impl_sanitizer_test.cc
@@ -39,7 +39,10 @@
              Stage(ast::PipelineStage::kFragment),
          });
 
-    GeneratorImpl& gen = SanitizeAndBuild();
+    Options opts = DefaultOptions();
+    opts.array_length_from_uniform.ubo_binding = sem::BindingPoint{0, 30};
+    opts.array_length_from_uniform.bindpoint_to_size_index.emplace(sem::BindingPoint{2, 1}, 1);
+    GeneratorImpl& gen = SanitizeAndBuild(opts);
 
     ASSERT_TRUE(gen.Generate()) << gen.error();
 
@@ -93,7 +96,10 @@
              Stage(ast::PipelineStage::kFragment),
          });
 
-    GeneratorImpl& gen = SanitizeAndBuild();
+    Options opts = DefaultOptions();
+    opts.array_length_from_uniform.ubo_binding = sem::BindingPoint{0, 30};
+    opts.array_length_from_uniform.bindpoint_to_size_index.emplace(sem::BindingPoint{2, 1}, 1);
+    GeneratorImpl& gen = SanitizeAndBuild(opts);
 
     ASSERT_TRUE(gen.Generate()) << gen.error();
 
@@ -151,7 +157,10 @@
              Stage(ast::PipelineStage::kFragment),
          });
 
-    GeneratorImpl& gen = SanitizeAndBuild();
+    Options opts = DefaultOptions();
+    opts.array_length_from_uniform.ubo_binding = sem::BindingPoint{0, 30};
+    opts.array_length_from_uniform.bindpoint_to_size_index.emplace(sem::BindingPoint{2, 1}, 1);
+    GeneratorImpl& gen = SanitizeAndBuild(opts);
 
     ASSERT_TRUE(gen.Generate()) << gen.error();