diff --git a/compiler/utils/assembler_test_base.h b/compiler/utils/assembler_test_base.h
index 7331863..bf73808 100644
--- a/compiler/utils/assembler_test_base.h
+++ b/compiler/utils/assembler_test_base.h
@@ -252,7 +252,7 @@
 
   // Remove comments emitted by objdump.
   std::string StripComments(const std::string& str) {
-    return std::regex_replace(str, std::regex(" +#.*"), "");
+    return std::regex_replace(str, std::regex(" +# .*"), "");
   }
 
   std::optional<ScratchDir> scratch_dir_;