diff --git a/PScope.h b/PScope.h
index 4e356cede..b6c31791a 100644
--- a/PScope.h
+++ b/PScope.h
@@ -72,7 +72,7 @@ class LexicalScope {
 	// Packages that are wildcard imported. When identifiers from
 	// these packages are referenced, they will be added to the
 	// explicit imports (IEEE 1800-2012 26.3).
-      std::set<PPackage*>potential_imports;
+      std::list<PPackage*>potential_imports;
 
 	// A task or function call may reference a task or function defined
 	// later in the scope. So here we stash the potential imports for
diff --git a/pform.cc b/pform.cc
index 34cd4042b..a04c301de 100644
--- a/pform.cc
+++ b/pform.cc
@@ -478,7 +478,7 @@ static PPackage*find_potential_import(const struct vlltype&loc, LexicalScope*sco
       assert(scope);
 
       PPackage*found_pkg = 0;
-      for (set<PPackage*>::const_iterator cur_pkg = scope->potential_imports.begin();
+      for (list<PPackage*>::const_iterator cur_pkg = scope->potential_imports.begin();
 	      cur_pkg != scope->potential_imports.end(); ++cur_pkg) {
 	    PPackage*search_pkg = *cur_pkg;
 	    map<perm_string,PNamedItem*>::const_iterator cur_sym
diff --git a/pform_package.cc b/pform_package.cc
index 100ae6b42..4acccce2d 100644
--- a/pform_package.cc
+++ b/pform_package.cc
@@ -124,10 +124,12 @@ void pform_package_import(const struct vlltype&loc, PPackage*pkg, const char*ide
 	    scope->explicit_imports[use_ident] = pkg;
 
       } else {
-	    set<PPackage*>::const_iterator cur_pkg
-		  = scope->potential_imports.find(pkg);
+	    list<PPackage*>::const_iterator cur_pkg
+		  = find(scope->potential_imports.begin(),
+                         scope->potential_imports.end(),
+                         pkg);
 	    if (cur_pkg == scope->potential_imports.end())
-		  scope->potential_imports.insert(pkg);
+		  scope->potential_imports.push_back(pkg);
       }
 }