diff --git a/deploy_tool/main.cpp b/deploy_tool/main.cpp
index e70bdc6..e311246 100644
--- a/deploy_tool/main.cpp
+++ b/deploy_tool/main.cpp
@@ -67,7 +67,7 @@ int depth = 1;
 bool need_qt = false, fake = false, is_ldd = true;
 PIString ldd, readelf, objdump, otool, out_dir, qt_dir, out_plugins_dir;
 PIStringList styles, lib_dirs, add_libs, platforms;
-PISet<PIString> all_libs, miss_libs, frameworks, miss_frameworks;
+PISet<PIString> all_libs, miss_libs, checked_libs, frameworks, miss_frameworks;
 
 
 PIString findLib(const PIString & l) {
@@ -82,6 +82,8 @@ PIString findLib(const PIString & l) {
 
 
 void procLdd(PIString file, bool ext_lib = false, int cur_depth = 0) {
+	if (checked_libs[file]) return;
+	checked_libs << file;
 	++cur_depth;
 	if (cur_depth > depth) return;
 	piCout << "scan" << file << "..." << cur_depth;