diff --git swiftpm.orig/Sources/Build/BuildDescription/ClangModuleBuildDescription.swift swiftpm/Sources/Build/BuildDescription/ClangModuleBuildDescription.swift
index 3aadda6b5..61c1c3532 100644
--- swiftpm.orig/Sources/Build/BuildDescription/ClangModuleBuildDescription.swift
+++ swiftpm/Sources/Build/BuildDescription/ClangModuleBuildDescription.swift
@@ -440,7 +440,7 @@ public final class ClangModuleBuildDescription {
         case .debug:
             return ["-O0"]
         case .release:
-            return ["-O2"]
+            return ["-O1"]
         }
     }