diff --git a/tools/opt/opt.cpp b/tools/opt/opt.cpp
index 64c08ab56af..0a945df7f7b 100644
--- a/tools/opt/opt.cpp
+++ b/tools/opt/opt.cpp
@@ -427,7 +427,7 @@ void AddStandardCompilePasses(PassManagerBase &PM) {
                              /*OptimizeSize=*/ false,
                              /*UnitAtATime=*/ true,
                              /*UnrollLoops=*/ true,
-                             /*SimplifyLibCalls=*/ true,
+                             !DisableSimplifyLibCalls,
                              /*HaveExceptions=*/ true,
                              InliningPass);
 }