diff --git a/llvm/include/llvm/ExecutionEngine/JITLink/JITLink.h b/llvm/include/llvm/ExecutionEngine/JITLink/JITLink.h
--- a/llvm/include/llvm/ExecutionEngine/JITLink/JITLink.h
+++ b/llvm/include/llvm/ExecutionEngine/JITLink/JITLink.h
@@ -354,13 +354,13 @@
 };
 
 // Align an address to conform with block alignment requirements.
-inline uint64_t alignToBlock(uint64_t Addr, Block &B) {
+inline uint64_t alignToBlock(uint64_t Addr, const Block &B) {
   uint64_t Delta = (B.getAlignmentOffset() - Addr) % B.getAlignment();
   return Addr + Delta;
 }
 
 // Align a orc::ExecutorAddr to conform with block alignment requirements.
-inline orc::ExecutorAddr alignToBlock(orc::ExecutorAddr Addr, Block &B) {
+inline orc::ExecutorAddr alignToBlock(orc::ExecutorAddr Addr, const Block &B) {
   return orc::ExecutorAddr(alignToBlock(Addr.getValue(), B));
 }