diff --git a/docs/3.0-migration-guide.md b/docs/3.0-migration-guide.md
index ef6df7ae5..bb21dedd8 100644
--- a/docs/3.0-migration-guide.md
+++ b/docs/3.0-migration-guide.md
@@ -320,7 +320,7 @@ This affects applications that call the `mbedtls_x509write_csr_set_extension`
 function.
 
 The API is changed to include the parameter `critical` which allow to mark an
-extension included in a CSR as critical. To get the previous behavior pass TODO
+extension included in a CSR as critical. To get the previous behavior pass 0.
 
 TLS now favors faster curves over larger curves
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