diff --git a/Sdtrig.adoc b/Sdtrig.adoc
index 6fe91cd7..2f63bce6 100644
--- a/Sdtrig.adoc
+++ b/Sdtrig.adoc
@@ -346,7 +346,7 @@ follow write-any-read-legal semantics. If a debugger writes an
 unsupported configuration, the register will read back a value that is
 supported (which may simply be a disabled trigger). This means that a
 debugger must always read back values it writes to `tdata` registers,
-unless it already knows already what is supported. Writes to one `tdata`
+unless it already knows what is supported. Writes to one `tdata`
 register must not modify the contents of other `tdata` registers, nor
 the configuration of any trigger besides the one that is currently
 selected.