diff --git a/Frameworks/io/src/path.cc b/Frameworks/io/src/path.cc
index 7fb9aeb3..02225dcd 100644
--- a/Frameworks/io/src/path.cc
+++ b/Frameworks/io/src/path.cc
@@ -653,14 +653,22 @@ namespace path
 		});
 
 		std::vector<size_t> levels(paths.size());
-		for(size_t i = 0; i < v.size(); ++i)
+		for(size_t i = 0; i < v.size(); )
 		{
+			std::string const& current = paths[v[i]];
 			size_t above = 0, below = 0;
+
 			if(i != 0)
-				above = count_slashes(paths[v[i]], paths[v[i-1]]);
-			if(i != v.size()-1)
-				below = count_slashes(paths[v[i]], paths[v[i+1]]);
-			levels[v[i]] = std::max(above, below);
+				above = count_slashes(current, paths[v[i-1]]);
+
+			size_t j = i;
+			while(j < v.size() && current == paths[v[j]])
+				++j;
+			if(j < v.size())
+				below = count_slashes(current, paths[v[j]]);
+
+			for(; i < j; ++i)
+				levels[v[i]] = std::max(above, below);
 		}
 
 		return levels;
diff --git a/Frameworks/io/tests/t_disambiguate_paths.cc b/Frameworks/io/tests/t_disambiguate_paths.cc
index 55939701..9901c768 100644
--- a/Frameworks/io/tests/t_disambiguate_paths.cc
+++ b/Frameworks/io/tests/t_disambiguate_paths.cc
@@ -40,6 +40,34 @@ public:
 		run_test(paths3, "qux — a/baz");
 	}
 
+	void test_disambiguate_paths_duplicates ()
+	{
+		std::vector<std::string> paths{
+			"/Users/duff/Projects/Avian",
+			"/Users/duff/Projects/TextMate",
+			"/Users/duff/public/macromates_com",
+			"/Users/duff/Projects/macromates_com",
+			"/Users/duff/public/macromates_com",
+			"/Users/duff/Projects/api_textmate_org",
+			"/Users/duff/Library/Application Support/TextMate",
+			"/Users/duff/Projects/Avian",
+			"/Users/duff/build/public/macromates_com",
+		};
+
+		std::vector<size_t> parents = path::disambiguate(paths);
+		TS_ASSERT_EQUALS(parents.size(), paths.size());
+
+		TS_ASSERT_EQUALS(parents[0], 0);
+		TS_ASSERT_EQUALS(parents[1], 1);
+		TS_ASSERT_EQUALS(parents[2], 2);
+		TS_ASSERT_EQUALS(parents[3], 1);
+		TS_ASSERT_EQUALS(parents[4], 2);
+		TS_ASSERT_EQUALS(parents[5], 0);
+		TS_ASSERT_EQUALS(parents[6], 1);
+		TS_ASSERT_EQUALS(parents[7], 0);
+		TS_ASSERT_EQUALS(parents[8], 2);
+	}
+
 	void test_localisation ()
 	{
 		test::jail_t jail;