diff --git a/clang/lib/Driver/Driver.cpp b/clang/lib/Driver/Driver.cpp
--- a/clang/lib/Driver/Driver.cpp
+++ b/clang/lib/Driver/Driver.cpp
@@ -2635,7 +2635,7 @@
       assert(CudaDeviceActions.size() == GpuArchList.size() &&
              "Expecting one action per GPU architecture.");
       assert(ToolChains.size() == 1 &&
-             "Expecting to have a sing CUDA toolchain.");
+             "Expecting to have a single CUDA toolchain.");
       for (unsigned I = 0, E = GpuArchList.size(); I != E; ++I)
         AddTopLevel(CudaDeviceActions[I], GpuArchList[I]);