diff --git a/reactos/ReactOS.rbuild b/reactos/ReactOS.rbuild
index d03f0f01287..d5ab7c4b995 100644
--- a/reactos/ReactOS.rbuild
+++ b/reactos/ReactOS.rbuild
@@ -24,12 +24,14 @@
     <define name="KDBG" value="1" />
     <property name="DBG_OR_KDBG" value="true" />
   </if>
-  <compilerflag>-O3</compilerflag>
-  <compilerflag>-fno-optimize-sibling-calls</compilerflag>
-  <compilerflag>-Wno-strict-aliasing</compilerflag>
-  <compilerflag>-ftracer</compilerflag>
-  <compilerflag>-momit-leaf-frame-pointer</compilerflag>
-  <compilerflag>-mpreferred-stack-boundary=2</compilerflag>
+  
+  <if property="GDB" value="0">
+    <compilerflag>-Os</compilerflag>
+    <compilerflag>-Wno-strict-aliasing</compilerflag>
+    <compilerflag>-ftracer</compilerflag>
+    <compilerflag>-momit-leaf-frame-pointer</compilerflag>
+    <compilerflag>-mpreferred-stack-boundary=2</compilerflag>
+  </if>
   <compilerflag>-Wpointer-arith</compilerflag>
 
   <include>.</include>