Index: lib/ubsan/ubsan_handlers.cc
===================================================================
--- lib/ubsan/ubsan_handlers.cc
+++ lib/ubsan/ubsan_handlers.cc
@@ -156,6 +156,9 @@
   if (ignoreReport(Loc, Opts, ET))
     return;
 
+  if (!IsSigned && flags()->silence_unsigned_overflow)
+    return;
+
   ScopedReport R(Opts, Loc, ET);
 
   if (IsSigned)
Index: test/ubsan/TestCases/Integer/negate-overflow.cpp
===================================================================
--- test/ubsan/TestCases/Integer/negate-overflow.cpp
+++ test/ubsan/TestCases/Integer/negate-overflow.cpp
@@ -1,10 +1,12 @@
 // RUN: %clangxx -fsanitize=signed-integer-overflow %s -o %t1 && %run %t1 2>&1 | FileCheck %s --check-prefix=CHECKS
 // RUN: %clangxx -fsanitize=unsigned-integer-overflow %s -o %t2 && %run %t2 2>&1 | FileCheck %s --check-prefix=CHECKU
+// RUN: %clangxx -fsanitize=unsigned-integer-overflow %s -o %t2 && %env_ubsan_opts=silence_unsigned_overflow=1 %run %t2 2>&1 | FileCheck %s --check-prefix=CHECKU-SILENT --allow-empty
 
 int main() {
   // CHECKS-NOT: runtime error
-  // CHECKU: negate-overflow.cpp:[[@LINE+2]]:3: runtime error: negation of 2147483648 cannot be represented in type 'unsigned int'
+  // CHECKU: negate-overflow.cpp:[[@LINE+3]]:3: runtime error: negation of 2147483648 cannot be represented in type 'unsigned int'
   // CHECKU-NOT: cast to an unsigned
+  // CHECKU-SILENT-NOT: runtime error
   -unsigned(-0x7fffffff - 1); // ok
   // CHECKS: negate-overflow.cpp:[[@LINE+2]]:3: runtime error: negation of -2147483648 cannot be represented in type 'int'; cast to an unsigned type to negate this value to itself
   // CHECKU-NOT: runtime error