Index: lld/ELF/Driver.cpp
===================================================================
--- lld/ELF/Driver.cpp
+++ lld/ELF/Driver.cpp
@@ -47,6 +47,7 @@
 #include "llvm/ADT/SetVector.h"
 #include "llvm/ADT/StringExtras.h"
 #include "llvm/ADT/StringSwitch.h"
+#include "llvm/ADT/UniqueVector.h"
 #include "llvm/Config/llvm-config.h"
 #include "llvm/LTO/LTO.h"
 #include "llvm/Object/Archive.h"
@@ -594,7 +595,10 @@
 
 static std::string getRpath(opt::InputArgList &args) {
   std::vector<StringRef> v = args::getStrings(args, OPT_rpath);
-  return llvm::join(v.begin(), v.end(), ":");
+  llvm::UniqueVector<StringRef> u;
+  for (StringRef p : v)
+      u.insert(p);
+  return llvm::join(u.begin(), u.end(), ":");
 }
 
 // Determines what we should do if there are remaining unresolved
Index: lld/test/ELF/rpath.test
===================================================================
--- /dev/null
+++ lld/test/ELF/rpath.test
@@ -0,0 +1,12 @@
+# REQUIRES: x86
+// RUN: llvm-mc -filetype=obj -triple=x86_64-pc-linux %s -o %t.o
+// RUN: ld.lld %t.o -rpath=/path1 -rpath=/path12 -rpath=/path2 -rpath=/path2 -rpath=/path1 -shared -o %t
+// RUN: llvm-readobj --dynamic-table %t | FileCheck %s
+
+// Degenerate case where an -rpath argument already contains a colon:
+// RUN: ld.lld %t.o -rpath=/path1 -rpath=/path1:/path2 -rpath=/path2 -shared -o %t
+// RUN: llvm-readobj --dynamic-table %t | FileCheck --check-prefix=DEGENERATE %s
+
+// CHECK: Library runpath: [/path1:/path12:/path2]
+
+// DEGENERATE: Library runpath: [/path1:/path1:/path2:/path2]