diff --git a/src/library/compiler/emit_cpp.cpp b/src/library/compiler/emit_cpp.cpp
index 50ebba577d..8b98a1dbaf 100644
--- a/src/library/compiler/emit_cpp.cpp
+++ b/src/library/compiler/emit_cpp.cpp
@@ -812,14 +812,14 @@ static void emit_fns(std::ostream & out, environment const & env) {
 
 static void emit_initialize(std::ostream & out, environment const & env, module_name const & m, list<module_name> const & deps) {
     for (module_name const & d : deps) {
-        out << "void _l_initialize_" << mangle(d) << "();\n";
+        out << "void initialize_" << mangle(d, false) << "();\n";
     }
     out << "static bool _G_initialized = false;\n";
-    out << "void _l_initialize_" << mangle(m) << "() {\n";
+    out << "void initialize_" << mangle(m, false) << "() {\n";
     out << " if (_G_initialized) return;\n";
     out << " _G_initialized = true;\n";
     for (module_name const & d : deps) {
-        out << " _l_initialize_" << mangle(d) << "();\n";
+        out << " initialize_" << mangle(d, false) << "();\n";
     }
     comp_decls ds = get_extension(env).m_code;
     for (comp_decl const & d : ds) {
diff --git a/src/library/compiler/name_mangling.cpp b/src/library/compiler/name_mangling.cpp
index 5a5ae1a6c2..5e87d0683e 100644
--- a/src/library/compiler/name_mangling.cpp
+++ b/src/library/compiler/name_mangling.cpp
@@ -20,12 +20,12 @@ static std::string mangle(std::string const & s) {
             } else if (c == '_') {
                 out += "__";
             } else {
-                out += "_x";
+                out += "_x_";
                 out += ('0' + (c / 16));
                 out += ('0' + (c % 16));
             }
         } else {
-            out += "_u";
+            out += "_u_";
             out += ('0' + (c / 4096));
             c %= 4096;
             out += ('0' + (c / 256));
@@ -47,18 +47,17 @@ static void mangle(name const & n, std::string & out) {
         out += "_";
     } else {
         lean_assert(n.is_string());
-        mangle(n.get_prefix(), out);
-        out += "_s";
-        std::string s = mangle(n.get_string().to_std_string());
-        unsigned len  = s.size();
-        out += std::to_string(len);
-        out += "_";
-        out += s;
+        if (!n.get_prefix().is_anonymous()) {
+            mangle(n.get_prefix(), out);
+            out += "_";
+        }
+        out += mangle(n.get_string().to_std_string());
     }
 }
 
-std::string mangle(name const & n) {
-    std::string out("_l");
+std::string mangle(name const & n, bool add_prefix) {
+    std::string out;
+    if (add_prefix) out += "l_";
     mangle(n, out);
     return out;
 }
diff --git a/src/library/compiler/name_mangling.h b/src/library/compiler/name_mangling.h
index 1028d1ed59..811b88e1ba 100644
--- a/src/library/compiler/name_mangling.h
+++ b/src/library/compiler/name_mangling.h
@@ -8,5 +8,5 @@ Author: Leonardo de Moura
 #include "util/name.h"
 
 namespace lean {
-std::string mangle(name const & n);
+std::string mangle(name const & n, bool add_prefix = true);
 }