diff --git a/lldb/test/Shell/Unwind/Inputs/call-asm.c b/lldb/test/Shell/Unwind/Inputs/call-asm.c
index b154c1ac1385d..778c16b36a761 100644
--- a/lldb/test/Shell/Unwind/Inputs/call-asm.c
+++ b/lldb/test/Shell/Unwind/Inputs/call-asm.c
@@ -1,3 +1,3 @@
-int asm_main() asm("asm_main");
-
+// Explicit mangling is necessary as on Darwin an underscore is prepended to the symbol.
+int asm_main() __asm("asm_main");
 int main() { return asm_main(); }