diff --git a/uppsrc/ide/Core/Core.h b/uppsrc/ide/Core/Core.h
index 3b61ccfc8..6627abdab 100644
--- a/uppsrc/ide/Core/Core.h
+++ b/uppsrc/ide/Core/Core.h
@@ -162,6 +162,8 @@ void   SetVar(const String& var, const String& value);
 String GetAnyFileName(const char *path);
 String GetAnyFileTitle(const char *path);
 String CatAnyPath(String path, const char *more);
+
+void   InvalidatePackageCache();
 String PackagePath(const String& name);
 String SourcePath(const String& package, const String& name);
 inline
diff --git a/uppsrc/ide/Core/Workspace.cpp b/uppsrc/ide/Core/Workspace.cpp
index c56b0724d..a0fafa243 100644
--- a/uppsrc/ide/Core/Workspace.cpp
+++ b/uppsrc/ide/Core/Workspace.cpp
@@ -173,7 +173,15 @@ bool IsFolder(const String& path)
 	return ff && ff.IsDirectory();
 }
 
-String PackagePath(const String& name) {
+VectorMap<String, String> package_cache;
+
+void InvalidatePackageCache()
+{
+	package_cache.Clear();
+}
+
+String PackagePath0(const String& name)
+{
 	String uppfile = NativePath(name);
 	if(IsFullPath(uppfile)) return NormalizePath(uppfile);
 	Vector<String> d = GetUppDirs();
@@ -187,6 +195,17 @@ String PackagePath(const String& name) {
 		                                GetFileName(uppfile)) + ".upp") : "";
 }
 
+String PackagePath(const String& name)
+{
+	int q = package_cache.Find(name);
+	if(q < 0) {
+		String h = PackagePath0(name);
+		package_cache.Add(name, h);
+		return h;
+	}
+	return package_cache[q];
+}
+
 String SourcePath(const String& package, const String& file) {
 	if(IsFullPath(file)) return NativePath(file);
 	return NormalizePath(AppendFileName(GetFileFolder(PackagePath(package)), file));
diff --git a/uppsrc/ide/UppDlg.cpp b/uppsrc/ide/UppDlg.cpp
index 454fcb29c..44a0a9790 100644
--- a/uppsrc/ide/UppDlg.cpp
+++ b/uppsrc/ide/UppDlg.cpp
@@ -576,6 +576,7 @@ PackageEditor::PackageEditor()
 }
 
 void EditPackages(const char *main, const char *startwith, String& cfg) {
+	InvalidatePackageCache();
 	PackageEditor pe;
 	pe.Sizeable();
 	StringStream in(cfg);
diff --git a/uppsrc/ide/UppWspc.cpp b/uppsrc/ide/UppWspc.cpp
index 1b8fff8c9..a9d48b43c 100644
--- a/uppsrc/ide/UppWspc.cpp
+++ b/uppsrc/ide/UppWspc.cpp
@@ -211,6 +211,7 @@ void WorkspaceWork::TouchFile(const String& path)
 
 void WorkspaceWork::PackageCursor()
 {
+	InvalidatePackageCache();
 	filelist.WhenBar.Clear();
 	actualpackage = GetActivePackage();
 	if(actualpackage.IsEmpty()) return;