diff --git a/lib/Dialect/LLHD/IR/LLHDOps.cpp b/lib/Dialect/LLHD/IR/LLHDOps.cpp
index 3a4e5f88b9..5f99fa4266 100644
--- a/lib/Dialect/LLHD/IR/LLHDOps.cpp
+++ b/lib/Dialect/LLHD/IR/LLHDOps.cpp
@@ -841,10 +841,6 @@ static LogicalResult verify(llhd::InstOp op) {
 
   auto proc = op->getParentOfType<ModuleOp>().lookupSymbol<llhd::ProcOp>(
       calleeAttr.getValue());
-  auto entity = op->getParentOfType<ModuleOp>().lookupSymbol<llhd::EntityOp>(
-      calleeAttr.getValue());
-
-  // Verify that the input and output types match the callee.
   if (proc) {
     auto type = proc.getType();
 
@@ -856,12 +852,16 @@ static LogicalResult verify(llhd::InstOp op) {
       return op.emitOpError(
           "incorrect number of outputs for proc instantiation");
 
-    for (size_t i = 0, e = type.getNumInputs(); i != e; ++i)
+    for (size_t i = 0, e = type.getNumInputs(); i != e; ++i) {
       if (op.getOperand(i).getType() != type.getInput(i))
         return op.emitOpError("operand type mismatch");
+    }
 
     return success();
   }
+
+  auto entity = op->getParentOfType<ModuleOp>().lookupSymbol<llhd::EntityOp>(
+      calleeAttr.getValue());
   if (entity) {
     auto type = entity.getType();
 
@@ -873,14 +873,51 @@ static LogicalResult verify(llhd::InstOp op) {
       return op.emitOpError(
           "incorrect number of outputs for entity instantiation");
 
-    for (size_t i = 0, e = type.getNumInputs(); i != e; ++i)
+    for (size_t i = 0, e = type.getNumInputs(); i != e; ++i) {
       if (op.getOperand(i).getType() != type.getInput(i))
         return op.emitOpError("operand type mismatch");
+    }
 
     return success();
   }
-  return op.emitOpError() << "'" << calleeAttr.getValue()
-                          << "' does not reference a valid proc or entity";
+
+  auto module = op->getParentOfType<ModuleOp>().lookupSymbol<hw::HWModuleOp>(
+      calleeAttr.getValue());
+  if (module) {
+    auto type = module.getType();
+
+    if (type.getNumInputs() != op.inputs().size())
+      return op.emitOpError(
+          "incorrect number of inputs for hw.module instantiation");
+
+    if (type.getNumResults() + type.getNumInputs() != op.getNumOperands())
+      return op.emitOpError(
+          "incorrect number of outputs for hw.module instantiation");
+
+    // Check input types
+    for (size_t i = 0, e = type.getNumInputs(); i != e; ++i) {
+      if (op.getOperand(i)
+              .getType()
+              .cast<llhd::SigType>()
+              .getUnderlyingType() != type.getInput(i))
+        return op.emitOpError("input type mismatch");
+    }
+
+    // Check output types
+    for (size_t i = 0, e = type.getNumResults(); i != e; ++i) {
+      if (op.getOperand(type.getNumInputs() + i)
+              .getType()
+              .cast<llhd::SigType>()
+              .getUnderlyingType() != type.getResult(i))
+        return op.emitOpError("output type mismatch");
+    }
+
+    return success();
+  }
+
+  return op.emitOpError()
+         << "'" << calleeAttr.getValue()
+         << "' does not reference a valid proc, entity, or hw.module";
 }
 
 FunctionType llhd::InstOp::getCalleeType() {
diff --git a/test/Dialect/LLHD/IR/inst-errors.mlir b/test/Dialect/LLHD/IR/inst-errors.mlir
index 0ffe1de2a2..0edeac0faa 100644
--- a/test/Dialect/LLHD/IR/inst-errors.mlir
+++ b/test/Dialect/LLHD/IR/inst-errors.mlir
@@ -28,7 +28,7 @@ llhd.entity @caller(%arg : !llhd.sig<i32>) -> () {
 // -----
 
 llhd.entity @caller() -> () {
-  // expected-error @+1 {{does not reference a valid proc or entity}}
+  // expected-error @+1 {{does not reference a valid proc, entity, or hw.module}}
   llhd.inst "does_not_exist" @does_not_exist() -> () : () -> ()
 }
 
@@ -41,3 +41,24 @@ llhd.entity @test_uniqueness() -> () {
   // expected-error @+1 {{Redefinition of instance named 'inst'!}}
   llhd.inst "inst" @empty() -> () : () -> ()
 }
+
+// -----
+
+hw.module @module(%arg0: i2) -> () {}
+
+llhd.entity @moduleTypeMismatch(%arg0: !llhd.sig<i3>) -> () {
+  // expected-error @+1 {{input type mismatch}}
+  llhd.inst "inst" @module(%arg0) -> () : (!llhd.sig<i3>) -> ()
+}
+
+// -----
+
+hw.module @module() -> (arg0: i2) {
+  %0 = hw.constant 0 : i2
+  hw.output %0 : i2
+}
+
+llhd.entity @moduleTypeMismatch() -> (%arg0: !llhd.sig<i3>) {
+  // expected-error @+1 {{output type mismatch}}
+  llhd.inst "inst" @module() -> (%arg0) : () -> !llhd.sig<i3>
+}
diff --git a/test/Dialect/LLHD/IR/inst.mlir b/test/Dialect/LLHD/IR/inst.mlir
index 2367c01eab..efbf8d426a 100644
--- a/test/Dialect/LLHD/IR/inst.mlir
+++ b/test/Dialect/LLHD/IR/inst.mlir
@@ -39,6 +39,12 @@ llhd.proc @proc(%arg0 : !llhd.sig<i32>, %arg1 : !llhd.sig<i16>) -> (%out0 : !llh
   llhd.halt
 }
 
+// CHECK-LABEL: @hwModule
+hw.module @hwModule(%arg0 : i32, %arg1 : i16) -> (arg2: i8) {
+  %0 = hw.constant 2 : i8
+  hw.output %0 : i8
+}
+
 // CHECK: llhd.entity @caller (%[[ARG0:.*]] : !llhd.sig<i32>, %[[ARG1:.*]] : !llhd.sig<i16>) -> (%[[OUT0:.*]] : !llhd.sig<i8>, %[[OUT1:.*]] : !llhd.sig<i4>) {
 llhd.entity @caller(%arg0 : !llhd.sig<i32>, %arg1 : !llhd.sig<i16>) -> (%out0 : !llhd.sig<i8>, %out1 : !llhd.sig<i4>) {
   // CHECK-NEXT: llhd.inst "empty_entity" @empty_entity() -> () : () -> ()
@@ -57,5 +63,7 @@ llhd.entity @caller(%arg0 : !llhd.sig<i32>, %arg1 : !llhd.sig<i16>) -> (%out0 :
   "llhd.inst"(%arg0, %arg1, %out0, %out1) {callee=@entity, operand_segment_sizes=dense<[2,2]> : vector<2xi32>, name="entity"} : (!llhd.sig<i32>, !llhd.sig<i16>, !llhd.sig<i8>, !llhd.sig<i4>) -> ()
   // CHECK-NEXT: llhd.inst "proc" @proc(%[[ARG0]], %[[ARG1]]) -> (%[[OUT0]], %[[OUT1]]) : (!llhd.sig<i32>, !llhd.sig<i16>) -> (!llhd.sig<i8>, !llhd.sig<i4>)
   "llhd.inst"(%arg0, %arg1, %out0, %out1) {callee=@proc, operand_segment_sizes=dense<[2,2]> : vector<2xi32>, name="proc"} : (!llhd.sig<i32>, !llhd.sig<i16>, !llhd.sig<i8>, !llhd.sig<i4>) -> ()
+  // CHECK-NEXT: llhd.inst "module" @hwModule(%[[ARG0]], %[[ARG1]]) -> (%[[OUT0]]) : (!llhd.sig<i32>, !llhd.sig<i16>) -> !llhd.sig<i8>
+  llhd.inst "module" @hwModule(%arg0, %arg1) -> (%out0) : (!llhd.sig<i32>, !llhd.sig<i16>) -> !llhd.sig<i8>
   // CHECK-NEXT: }
 }