diff --git a/include/libopencm3/stm32/tools.h b/include/libopencm3/stm32/tools.h
index e1724339..807aa60b 100644
--- a/include/libopencm3/stm32/tools.h
+++ b/include/libopencm3/stm32/tools.h
@@ -34,8 +34,11 @@
 #define CLR_REG_BIT(REG, BIT)	SET_REG(REG, (~BIT))
 
 /* Clear register bit masking out some bits that must not be touched. */
+#define CLR_REG_BIT_MSK_AND_SET(REG, MSK, BIT, EXTRA_BITS) \
+		SET_REG(REG, (GET_REG(REG) & MSK & (~BIT)) | (EXTRA_BITS))
+
 #define CLR_REG_BIT_MSK(REG, MSK, BIT) \
-		SET_REG(REG, (GET_REG(REG) & MSK & (~BIT)))
+		CLR_REG_BIT_MSK_AND_SET(REG, MSK, BIT, 0)
 
 /* Get masked out bit value. */
 #define GET_REG_BIT(REG, BIT)	(GET_REG(REG) & BIT)
@@ -50,7 +53,7 @@
  *
  * TODO: We may need a faster implementation of that one?
  */
-#define TOG_SET_REG_BIT_MSK(REG, MSK, BIT)				\
+#define TOG_SET_REG_BIT_MSK_AND_SET(REG, MSK, BIT, EXTRA_BITS)		\
 do {									\
 	register uint16_t toggle_mask = GET_REG(REG) & (MSK);		\
 	register uint16_t bit_selector;					\
@@ -59,7 +62,10 @@ do {									\
 			toggle_mask ^= bit_selector;			\
 		}							\
 	}								\
-	SET_REG(REG, toggle_mask);					\
+	SET_REG(REG, toggle_mask | (EXTRA_BITS));			\
 } while (0)
 
+#define TOG_SET_REG_BIT_MSK(REG, MSK, BIT) \
+	TOG_SET_REG_BIT_MSK_AND_SET(REG, MSK, BIT, 0)
+
 #endif