diff --git a/main.cc b/main.cc
index 8b93f1c62..057b70ac2 100644
--- a/main.cc
+++ b/main.cc
@@ -1126,6 +1126,8 @@ int main(int argc, char*argv[])
 	    rc += pform_parse(source_files[idx]);
       }
 
+      pform_finish();
+
       if (pf_path) {
 	    ofstream out (pf_path);
 	    out << "PFORM DUMP NATURES:" << endl;
diff --git a/parse_api.h b/parse_api.h
index d95420916..da43030e1 100644
--- a/parse_api.h
+++ b/parse_api.h
@@ -58,6 +58,8 @@ extern void pform_dump(std::ostream&out, const PTaskFunc*tf);
  */
 extern int pform_parse(const char*path);
 
+extern void pform_finish();
+
 extern std::string vl_file;
 
 extern void pform_set_timescale(int units, int prec, const char*file,
diff --git a/pform.cc b/pform.cc
index e8aac1089..9b19f9dba 100644
--- a/pform.cc
+++ b/pform.cc
@@ -405,17 +405,22 @@ LexicalScope* pform_peek_scope(void)
       return lexical_scope;
 }
 
-void pform_pop_scope()
+static void pform_check_possible_imports(LexicalScope *scope)
 {
-      LexicalScope*scope = lexical_scope;
-      assert(scope);
-
       map<perm_string,PPackage*>::const_iterator cur;
       for (cur = scope->possible_imports.begin(); cur != scope->possible_imports.end(); ++cur) {
             if (scope->local_symbols.find(cur->first) == scope->local_symbols.end())
                   scope->explicit_imports[cur->first] = cur->second;
       }
       scope->possible_imports.clear();
+}
+
+void pform_pop_scope()
+{
+      LexicalScope*scope = lexical_scope;
+      assert(scope);
+
+      pform_check_possible_imports(scope);
 
       lexical_scope = scope->parent_scope();
       assert(lexical_scope);
@@ -3406,3 +3411,11 @@ int pform_parse(const char*path)
       destroy_lexor();
       return error_count;
 }
+
+void pform_finish()
+{
+      // Wait until all parsing is done and all symbols in the unit scope are
+      // known before importing possible imports.
+      for (auto unit : pform_units)
+	    pform_check_possible_imports(unit);
+}