diff --git a/lib/Driver/ToolChains/NetBSD.cpp b/lib/Driver/ToolChains/NetBSD.cpp
index 73e230b3ea4b..6dba5b1a5925 100644
--- a/lib/Driver/ToolChains/NetBSD.cpp
+++ b/lib/Driver/ToolChains/NetBSD.cpp
@@ -457,3 +457,11 @@ SanitizerMask NetBSD::getSupportedSanitizers() const {
   }
   return Res;
 }
+
+void NetBSD::addClangTargetOptions(const ArgList &,
+                                   ArgStringList &CC1Args,
+                                   Action::OffloadKind) const {
+  const SanitizerArgs &SanArgs = getSanitizerArgs();
+  if (SanArgs.hasAnySanitizer())
+    CC1Args.push_back("-D_REENTRANT");
+}
diff --git a/lib/Driver/ToolChains/NetBSD.h b/lib/Driver/ToolChains/NetBSD.h
index 49e3a58d02c3..ae0865fd6573 100644
--- a/lib/Driver/ToolChains/NetBSD.h
+++ b/lib/Driver/ToolChains/NetBSD.h
@@ -76,6 +76,10 @@ class LLVM_LIBRARY_VISIBILITY NetBSD : public Generic_ELF {
 
   SanitizerMask getSupportedSanitizers() const override;
 
+  void addClangTargetOptions(const llvm::opt::ArgList &DriverArgs,
+                             llvm::opt::ArgStringList &CC1Args,
+                             Action::OffloadKind DeviceOffloadKind) const override;
+
 protected:
   Tool *buildAssembler() const override;
   Tool *buildLinker() const override;