diff --git a/elab_expr.cc b/elab_expr.cc
index 2ee8f8510..be49e5c18 100644
--- a/elab_expr.cc
+++ b/elab_expr.cc
@@ -4720,7 +4720,7 @@ unsigned PENewClass::test_width(Design*, NetScope*, width_mode_t&)
  */
 NetExpr* PENewClass::elaborate_expr_constructor_(Design*des, NetScope*scope,
 						 const netclass_t*ctype,
-						 NetExpr*obj, unsigned flags) const
+						 NetExpr*obj, unsigned /*flags*/) const
 {
 	// If there is an initializer function, then pass the object
 	// through that function first. Note tha the initializer
diff --git a/nettypes.cc b/nettypes.cc
index d7d5c0883..1a36b177a 100644
--- a/nettypes.cc
+++ b/nettypes.cc
@@ -63,7 +63,7 @@ bool ivl_type_s::type_compatible(ivl_type_t that) const
       return test_compatibility(that);
 }
 
-bool ivl_type_s::test_compatibility(const ivl_type_s*that) const
+bool ivl_type_s::test_compatibility(const ivl_type_s* /*that*/) const
 {
       return false;
 }
diff --git a/tgt-blif/blif.cc b/tgt-blif/blif.cc
index 3d121ebd5..82bc83535 100644
--- a/tgt-blif/blif.cc
+++ b/tgt-blif/blif.cc
@@ -55,7 +55,7 @@ int blif_errors = 0;
 
 static void emit_blif(const char*blif_path, ivl_design_t des, ivl_scope_t model);
 
-static int process_scan_fun(ivl_process_t net, void*raw)
+static int process_scan_fun(ivl_process_t net, void* /*raw*/)
 {
       fprintf(stderr, "%s:%u: sorry: BLIF: Processes not supported yet.\n",
 	      ivl_process_file(net), ivl_process_lineno(net));