diff --git a/clang/lib/Driver/ToolChains/CommonArgs.cpp b/clang/lib/Driver/ToolChains/CommonArgs.cpp
--- a/clang/lib/Driver/ToolChains/CommonArgs.cpp
+++ b/clang/lib/Driver/ToolChains/CommonArgs.cpp
@@ -632,6 +632,11 @@
     CmdArgs.push_back(
         Args.MakeArgString(Twine("-plugin-opt=stats-file=") + StatsFile));
 
+  // Setup crash diagnostics dir.
+  if (Arg *A = Args.getLastArg(options::OPT_fcrash_diagnostics_dir))
+    CmdArgs.push_back(Args.MakeArgString(
+        Twine("-plugin-opt=-crash-diagnostics-dir=") + A->getValue()));
+
   addX86AlignBranchArgs(D, Args, CmdArgs, /*IsLTO=*/true);
 
   // Handle remark diagnostics on screen options: '-Rpass-*'.
diff --git a/clang/test/Driver/crash-diagnostics-dir-2.c b/clang/test/Driver/crash-diagnostics-dir-2.c
--- a/clang/test/Driver/crash-diagnostics-dir-2.c
+++ b/clang/test/Driver/crash-diagnostics-dir-2.c
@@ -3,3 +3,12 @@
 // OPTION: "-crash-diagnostics-dir=mydumps"
 // RUN: %clang -### -c %s 2>&1 | FileCheck %s --check-prefix=NOOPTION
 // NOOPTION-NOT: "-crash-diagnostics-dir
+
+// RUN: %clang -### -fcrash-diagnostics-dir=mydumps -flto %s 2>&1 \
+// RUN:     | FileCheck %s --check-prefix=LTO-OPTION
+// LTO-OPTION: "-cc1"
+// LTO-OPTION: "-plugin-opt=-crash-diagnostics-dir=mydumps"
+
+// RUN: %clang -### -flto %s 2>&1 | FileCheck %s --check-prefix=LTO-NOOPTION
+// LTO-NOOPTION: "-cc1"
+// LTO-NOOPTION-NOT: "-plugin-opt=-crash-diagnostics-dir=mydumps"