diff --git a/llvm/lib/Fuzzer/test/fuzzer.test b/llvm/lib/Fuzzer/test/fuzzer.test
index 8c5d148..cff7d6f 100644
--- a/llvm/lib/Fuzzer/test/fuzzer.test
+++ b/llvm/lib/Fuzzer/test/fuzzer.test
@@ -5,6 +5,9 @@
 RUN: not LLVMFuzzer-NullDerefTest %S/hi.txt 2>&1 | FileCheck %s --check-prefix=SingleInput
 SingleInput-NOT: Test unit written to ./crash-
 
+# only_ascii mode. Will perform some minimal self-validation.
+RUN: LLVMFuzzer-SimpleTest -only_ascii=1 2>&1
+
 RUN: LLVMFuzzer-SimpleCmpTest -max_total_time=1 2>&1 | FileCheck %s --check-prefix=MaxTotalTime
 MaxTotalTime: Done {{.*}} runs in {{.}} second(s)