--- a/common/server/crash-dump.cpp
+++ b/common/server/crash-dump.cpp
@@ -116,6 +116,8 @@
   crash_dump_write_reg(LITERAL_WITH_LENGTH("R15=0x"), uc->uc_mcontext.gregs[REG_R15], buffer);
   
 #elif defined(__aarch64__)
+  const auto *uc = static_cast<ucontext_t *>(ucontext);
+
   crash_dump_write_reg(LITERAL_WITH_LENGTH("SP=0x"), uc->uc_mcontext.sp, buffer);
   crash_dump_write_reg(LITERAL_WITH_LENGTH("PC=0x"), uc->uc_mcontext.pc, buffer);
   crash_dump_write_reg(LITERAL_WITH_LENGTH("PSTATE=0x"), uc->uc_mcontext.pstate, buffer);