diff --git a/readme.txt b/readme.txt
index 9e7e730..5df6c0f 100644
--- a/readme.txt
+++ b/readme.txt
@@ -24,7 +24,7 @@ On Debian, it is sufficient to run this command:
 
 To build Calcite, run these commands:
   sh get-dependencies.sh
-  sh make-build.sh
+  sh make-build.sh release
   ninja
 
 This will build a disk image at "build/disk.iso" that can be booted with
@@ -43,13 +43,13 @@ Then, just run "gdb -x qemu.gdb". Calcite will be booted in QEMU, and GDB will
 be attached to it. Use "c" or "continue" in GDB to start execution.
 
 While debugging, it is useful to disable optimizations and enable debugging
-information. In "make-build.sh", under COMMON_CC_EXTRA_FLAGS, you can change
-"-O3" to "-O0 -ggdb". Then, run these commands to rebuild:
-  rm -r build
-  rm build.ninja
-  sh make-build.sh
+information. If you already built Calcite in "release" mode, run:
+  rm -r build build.ninja
+  sh make-build.sh debug
   ninja
 
+If you did not already built Calcite, then you do not need the first command.
+
 === License
 
 Calcite is Copyright 2025 Benji Dial, and licensed under the GNU GPL v3. See