diff --git a/srcpkgs/llvm-libunwind/patches/fix-unsigned-long-long-shift.patch b/srcpkgs/llvm-libunwind/patches/fix-unsigned-long-long-shift.patch
new file mode 100644
index 00000000000..8c20256ceab
--- /dev/null
+++ b/srcpkgs/llvm-libunwind/patches/fix-unsigned-long-long-shift.patch
@@ -0,0 +1,15 @@
+Source: @pullmoll
+Upstream: no
+Reason: -1ULL is not a signed long long but the result is signed.
+
+--- src/AddressSpace.hpp	2019-05-30 06:40:21.000000000 +0200
++++ src/AddressSpace.hpp	2020-03-04 22:55:16.140731907 +0100
+@@ -288,7 +288,7 @@
+   } while (byte & 0x80);
+   // sign extend negative numbers
+   if ((byte & 0x40) != 0)
+-    result |= (-1ULL) << bit;
++    result |= (-1LL) << bit;
+   addr = (pint_t) p;
+   return result;
+ }