diff --git a/llvm/lib/MC/MCAssembler.cpp b/llvm/lib/MC/MCAssembler.cpp
--- a/llvm/lib/MC/MCAssembler.cpp
+++ b/llvm/lib/MC/MCAssembler.cpp
@@ -273,7 +273,7 @@
     "FKF_IsAlignedDownTo32Bits is only allowed on PC-relative fixups!");
 
   if (IsPCRel) {
-    uint32_t Offset = Layout.getFragmentOffset(DF) + Fixup.getOffset();
+    uint64_t Offset = Layout.getFragmentOffset(DF) + Fixup.getOffset();
 
     // A number of ARM fixups in Thumb mode require that the effective PC
     // address be determined as the 32-bit aligned version of the actual offset.
diff --git a/llvm/test/MC/AArch64/fixup-out-of-range-64-bit.s b/llvm/test/MC/AArch64/fixup-out-of-range-64-bit.s
new file mode 100644
--- /dev/null
+++ b/llvm/test/MC/AArch64/fixup-out-of-range-64-bit.s
@@ -0,0 +1,10 @@
+// RUN: not llvm-mc -triple aarch64--none-eabi -filetype obj < %s -o /dev/null 2>&1 | FileCheck %s
+
+distant:
+  .byte 0
+
+  .space 1<<32
+  .balign 8
+
+// CHECK: :[[@LINE+1]]:{{[0-9]+}}: error: fixup value out of range
+  b distant
\ No newline at end of file