diff --git a/lib/MC/MCAssembler.cpp b/lib/MC/MCAssembler.cpp
index cbbc0ac..3c9487b 100644
--- a/lib/MC/MCAssembler.cpp
+++ b/lib/MC/MCAssembler.cpp
@@ -691,7 +691,9 @@
 bool MCAssembler::RelaxLEB(MCAsmLayout &Layout, MCLEBFragment &LF) {
   int64_t Value = 0;
   uint64_t OldSize = LF.getContents().size();
-  LF.getValue().EvaluateAsAbsolute(Value, Layout);
+  bool IsAbs = LF.getValue().EvaluateAsAbsolute(Value, Layout);
+  (void)IsAbs;
+  assert(IsAbs);
   SmallString<8> &Data = LF.getContents();
   Data.clear();
   raw_svector_ostream OSE(Data);