diff --git a/clang/lib/Driver/ToolChains/Clang.cpp b/clang/lib/Driver/ToolChains/Clang.cpp
--- a/clang/lib/Driver/ToolChains/Clang.cpp
+++ b/clang/lib/Driver/ToolChains/Clang.cpp
@@ -2544,7 +2544,8 @@
 static void RenderTrivialAutoVarInitOptions(const Driver &D,
                                             const ToolChain &TC,
                                             const ArgList &Args,
-                                            ArgStringList &CmdArgs) {
+                                            ArgStringList &CmdArgs,
+                                            const InputInfo &Input) {
   auto DefaultTrivialAutoVarInit = TC.GetDefaultTrivialAutoVarInit();
   StringRef TrivialAutoVarInit = "";
 
@@ -2578,7 +2579,9 @@
     }
 
   if (!TrivialAutoVarInit.empty()) {
-    if (TrivialAutoVarInit == "zero" && !Args.hasArg(options::OPT_enable_trivial_var_init_zero))
+    if (TrivialAutoVarInit == "zero" &&
+        !Args.hasArg(options::OPT_enable_trivial_var_init_zero) &&
+        (Input.getType() != types::TY_C))
       D.Diag(diag::err_drv_trivial_auto_var_init_zero_disabled);
     CmdArgs.push_back(
         Args.MakeArgString("-ftrivial-auto-var-init=" + TrivialAutoVarInit));
@@ -4623,7 +4626,7 @@
     CmdArgs.push_back(Args.MakeArgString("-mspeculative-load-hardening"));
 
   RenderSSPOptions(TC, Args, CmdArgs, KernelOrKext);
-  RenderTrivialAutoVarInitOptions(D, TC, Args, CmdArgs);
+  RenderTrivialAutoVarInitOptions(D, TC, Args, CmdArgs, Input);
 
   // Translate -mstackrealign
   if (Args.hasFlag(options::OPT_mstackrealign, options::OPT_mno_stackrealign,
diff --git a/clang/test/Driver/clang_f_opts.c b/clang/test/Driver/clang_f_opts.c
--- a/clang/test/Driver/clang_f_opts.c
+++ b/clang/test/Driver/clang_f_opts.c
@@ -566,7 +566,10 @@
 // RUN: %clang -### -S -ftrivial-auto-var-init=uninitialized %s 2>&1 | FileCheck -check-prefix=CHECK-TRIVIAL-UNINIT %s
 // RUN: %clang -### -S -ftrivial-auto-var-init=pattern %s 2>&1 | FileCheck -check-prefix=CHECK-TRIVIAL-PATTERN %s
 // RUN: %clang -### -S -ftrivial-auto-var-init=zero -enable-trivial-auto-var-init-zero-knowing-it-will-be-removed-from-clang %s 2>&1 | FileCheck -check-prefix=CHECK-TRIVIAL-ZERO-GOOD %s
-// RUN: %clang -### -S -ftrivial-auto-var-init=zero %s 2>&1 | FileCheck -check-prefix=CHECK-TRIVIAL-ZERO-BAD %s
+// RUN: %clang -### -S -ftrivial-auto-var-init=zero %s 2>&1 | FileCheck -check-prefix=CHECK-TRIVIAL-ZERO-GOOD %s
+// RUN: %clangxx -### -S -ftrivial-auto-var-init=zero -enable-trivial-auto-var-init-zero-knowing-it-will-be-removed-from-clang %s 2>&1 | FileCheck -check-prefix=CHECK-TRIVIAL-ZERO-GOOD %s
+// RUN: %clangxx -### -S -ftrivial-auto-var-init=zero %s 2>&1 | FileCheck -check-prefix=CHECK-TRIVIAL-ZERO-BAD %s
+
 // CHECK-TRIVIAL-UNINIT-NOT: hasn't been enabled
 // CHECK-TRIVIAL-PATTERN-NOT: hasn't been enabled
 // CHECK-TRIVIAL-ZERO-GOOD-NOT: hasn't been enabled