diff --git a/lib/std/core/allocators/temp_allocator.c3 b/lib/std/core/allocators/temp_allocator.c3
index 6b8ac49b8..fd5626c4a 100644
--- a/lib/std/core/allocators/temp_allocator.c3
+++ b/lib/std/core/allocators/temp_allocator.c3
@@ -80,7 +80,7 @@ fn void TempAllocator.reset(&self, usz mark) @dynamic
 			usz cleaned = self.used - mark;
 			if (cleaned > 0)
 			{
-				$if env::COMPILER_SAFE_MODE:
+				$if env::COMPILER_SAFE_MODE && !env::ADDRESS_SANITIZER:
 					self.data[mark : cleaned] = 0xAA;
 				$endif
 				asan::poison_memory_region(&self.data[mark], cleaned);
diff --git a/releasenotes.md b/releasenotes.md
index fc798110b..2cdb5c99a 100644
--- a/releasenotes.md
+++ b/releasenotes.md
@@ -82,6 +82,7 @@
 - Do not link "ld" on Linux with no libc.
 - Fix bug when multiple `$else` clauses followed an `$if` #1824.
 - Report the correct type as not having a method when access fails #1828.
+- Prevent temp arena scribbling from causing an asan warning. #1825
 
 ### Stdlib changes
 - Increase BitWriter.write_bits limit up to 32 bits.