diff --git a/boards/b-l072z-lrwan1/doc.txt b/boards/b-l072z-lrwan1/doc.md
similarity index 94%
rename from boards/b-l072z-lrwan1/doc.txt
rename to boards/b-l072z-lrwan1/doc.md
index f75ba85161..c09c7f3d3f 100644
--- a/boards/b-l072z-lrwan1/doc.txt
+++ b/boards/b-l072z-lrwan1/doc.md
@@ -1,5 +1,3 @@
-/**
 @defgroup    boards_b-l072z-lrwan1 ST B-L072Z-LRWAN1 LoRa discovery
 @ingroup     boards
 @brief       Support for the ST B-L072Z-LRWAN1 board
- */
diff --git a/boards/b-l475e-iot01a/doc.txt b/boards/b-l475e-iot01a/doc.md
similarity index 94%
rename from boards/b-l475e-iot01a/doc.txt
rename to boards/b-l475e-iot01a/doc.md
index df4f2cf531..a8f9563dc9 100644
--- a/boards/b-l475e-iot01a/doc.txt
+++ b/boards/b-l475e-iot01a/doc.md
@@ -1,5 +1,3 @@
-/**
 @defgroup    boards_b-l475e-iot01a ST B-L475E-IOT01A
 @ingroup     boards
 @brief       Support for the ST B-L475E-IOT01A board
- */
diff --git a/boards/b-u585i-iot02a/doc.txt b/boards/b-u585i-iot02a/doc.md
similarity index 99%
rename from boards/b-u585i-iot02a/doc.txt
rename to boards/b-u585i-iot02a/doc.md
index 9c9df54292..edb0c3da24 100644
--- a/boards/b-u585i-iot02a/doc.txt
+++ b/boards/b-u585i-iot02a/doc.md
@@ -1,4 +1,3 @@
-/**
 @defgroup    boards_b-u585i-iot02a STM32 B-U585I-IOT02A
 @ingroup     boards
 @brief       Support for the STM32 B-U585I-IOT02A
@@ -39,5 +38,3 @@ toolchain.
 
 **Important notice:** With GCC 10, the `tests/sys/malloc` application doesn't work.
 To use malloc, prefer GCC 9 which seems to work better.
-
- */