diff --git a/src/common/util.cpp b/src/common/util.cpp
index 3f330fa13..329352e94 100644
--- a/src/common/util.cpp
+++ b/src/common/util.cpp
@@ -827,4 +827,22 @@ std::string get_nix_version_display_string()
       return false;
     return true;
   }
+
+  boost::optional<std::pair<uint32_t, uint32_t>> parse_subaddress_lookahead(const std::string& str)
+  {
+    auto pos = str.find(":");
+    bool r = pos != std::string::npos;
+    uint32_t major;
+    r = r && epee::string_tools::get_xtype_from_string(major, str.substr(0, pos));
+    uint32_t minor;
+    r = r && epee::string_tools::get_xtype_from_string(minor, str.substr(pos + 1));
+    if (r)
+    {
+      return std::make_pair(major, minor);
+    }
+    else
+    {
+      return {};
+    }
+  }
 }
diff --git a/src/common/util.h b/src/common/util.h
index 7caf0e3c5..dc426830b 100644
--- a/src/common/util.h
+++ b/src/common/util.h
@@ -32,6 +32,7 @@
 
 #include <boost/thread/locks.hpp>
 #include <boost/thread/mutex.hpp>
+#include <boost/optional.hpp>
 #include <system_error>
 #include <csignal>
 #include <cstdio>
@@ -214,4 +215,6 @@ namespace tools
   bool sha256sum(const std::string &filename, crypto::hash &hash);
 
   bool is_hdd(const char *path);
+
+  boost::optional<std::pair<uint32_t, uint32_t>> parse_subaddress_lookahead(const std::string& str);
 }
diff --git a/src/simplewallet/simplewallet.cpp b/src/simplewallet/simplewallet.cpp
index 90c3da6ca..62f220a1e 100644
--- a/src/simplewallet/simplewallet.cpp
+++ b/src/simplewallet/simplewallet.cpp
@@ -379,21 +379,10 @@ namespace
 
   boost::optional<std::pair<uint32_t, uint32_t>> parse_subaddress_lookahead(const std::string& str)
   {
-    auto pos = str.find(":");
-    bool r = pos != std::string::npos;
-    uint32_t major;
-    r = r && epee::string_tools::get_xtype_from_string(major, str.substr(0, pos));
-    uint32_t minor;
-    r = r && epee::string_tools::get_xtype_from_string(minor, str.substr(pos + 1));
-    if (r)
-    {
-      return std::make_pair(major, minor);
-    }
-    else
-    {
+    auto r = tools::parse_subaddress_lookahead(str);
+    if (!r)
       fail_msg_writer() << tr("invalid format for subaddress lookahead; must be <major>:<minor>");
-      return {};
-    }
+    return r;
   }
 
   void handle_transfer_exception(const std::exception_ptr &e, bool trusted_daemon)