diff --git a/cpu/atmega1281/include/default_timer_config.h b/cpu/atmega1281/include/default_timer_config.h
index 41fb5f7857..5cb1aaadf2 100644
--- a/cpu/atmega1281/include/default_timer_config.h
+++ b/cpu/atmega1281/include/default_timer_config.h
@@ -29,7 +29,7 @@ extern "C" {
 
 #ifndef TIMER_NUMOF
 #define TIMER_NUMOF         (2U)
-#define TIMER_CHANNELS      (3)
+#define TIMER_CHANNEL_NUMOF (3)
 
 #define TIMER_0             MEGA_TIMER1
 #define TIMER_0_MASK        &TIMSK1
diff --git a/cpu/atmega1284p/include/default_timer_config.h b/cpu/atmega1284p/include/default_timer_config.h
index 56eac636de..62fbdb2afb 100644
--- a/cpu/atmega1284p/include/default_timer_config.h
+++ b/cpu/atmega1284p/include/default_timer_config.h
@@ -28,7 +28,7 @@ extern "C" {
 
 #ifndef TIMER_NUMOF
 #define TIMER_NUMOF         (2U)
-#define TIMER_CHANNELS      (2)
+#define TIMER_CHANNEL_NUMOF (2)
 
 #define TIMER_0             MEGA_TIMER1
 #define TIMER_0_MASK        &TIMSK1
diff --git a/cpu/atmega128rfa1/include/default_timer_config.h b/cpu/atmega128rfa1/include/default_timer_config.h
index e3a7901e04..3f193cee61 100644
--- a/cpu/atmega128rfa1/include/default_timer_config.h
+++ b/cpu/atmega128rfa1/include/default_timer_config.h
@@ -26,7 +26,7 @@ extern "C" {
 
 #ifndef TIMER_NUMOF
 #define TIMER_NUMOF         (3U)
-#define TIMER_CHANNELS      (3)
+#define TIMER_CHANNEL_NUMOF (3)
 
 #define TIMER_0             MEGA_TIMER4
 #define TIMER_0_MASK        &TIMSK4
diff --git a/cpu/atmega2560/include/default_timer_config.h b/cpu/atmega2560/include/default_timer_config.h
index b38e8fe312..b3d850a259 100644
--- a/cpu/atmega2560/include/default_timer_config.h
+++ b/cpu/atmega2560/include/default_timer_config.h
@@ -29,7 +29,7 @@ extern "C" {
 
 #ifndef TIMER_NUMOF
 #define TIMER_NUMOF         (2U)
-#define TIMER_CHANNELS      (3)
+#define TIMER_CHANNEL_NUMOF (3)
 
 #define TIMER_0             MEGA_TIMER1
 #define TIMER_0_MASK        &TIMSK1
diff --git a/cpu/atmega256rfr2/include/default_timer_config.h b/cpu/atmega256rfr2/include/default_timer_config.h
index 8670c66553..a96cdde2cb 100644
--- a/cpu/atmega256rfr2/include/default_timer_config.h
+++ b/cpu/atmega256rfr2/include/default_timer_config.h
@@ -26,7 +26,7 @@ extern "C" {
 
 #ifndef TIMER_NUMOF
 #define TIMER_NUMOF         (3U)
-#define TIMER_CHANNELS      (3)
+#define TIMER_CHANNEL_NUMOF (3)
 
 #define TIMER_0             MEGA_TIMER4
 #define TIMER_0_MASK        &TIMSK4
diff --git a/cpu/atmega328p/include/default_timer_config.h b/cpu/atmega328p/include/default_timer_config.h
index b1d39ecc93..08e3ffebeb 100644
--- a/cpu/atmega328p/include/default_timer_config.h
+++ b/cpu/atmega328p/include/default_timer_config.h
@@ -27,7 +27,7 @@ extern "C" {
 
 #ifndef TIMER_NUMOF
 #define TIMER_NUMOF         (1U)
-#define TIMER_CHANNELS      (2)
+#define TIMER_CHANNEL_NUMOF (2)
 
 #define TIMER_0             MEGA_TIMER1
 #define TIMER_0_MASK        &TIMSK1
diff --git a/cpu/atmega32u4/include/default_timer_config.h b/cpu/atmega32u4/include/default_timer_config.h
index b0d89240a1..fe454f8435 100644
--- a/cpu/atmega32u4/include/default_timer_config.h
+++ b/cpu/atmega32u4/include/default_timer_config.h
@@ -26,7 +26,7 @@ extern "C" {
 
 #ifndef TIMER_NUMOF
 #define TIMER_NUMOF         (2U)
-#define TIMER_CHANNELS      (3)
+#define TIMER_CHANNEL_NUMOF (3)
 
 #define TIMER_0             MEGA_TIMER1
 #define TIMER_0_MASK        &TIMSK1
diff --git a/cpu/atmega_common/periph/timer.c b/cpu/atmega_common/periph/timer.c
index 45229de5f7..eadfc4ddc5 100644
--- a/cpu/atmega_common/periph/timer.c
+++ b/cpu/atmega_common/periph/timer.c
@@ -78,17 +78,17 @@ static unsigned _oneshot;
 
 static inline void set_oneshot(tim_t tim, int chan)
 {
-    _oneshot |= (1 << chan) << (TIMER_CHANNELS * tim);
+    _oneshot |= (1 << chan) << (TIMER_CHANNEL_NUMOF * tim);
 }
 
 static inline void clear_oneshot(tim_t tim, int chan)
 {
-    _oneshot &= ~((1 << chan) << (TIMER_CHANNELS * tim));
+    _oneshot &= ~((1 << chan) << (TIMER_CHANNEL_NUMOF * tim));
 }
 
 static inline bool is_oneshot(tim_t tim, int chan)
 {
-    return _oneshot & ((1 << chan) << (TIMER_CHANNELS * tim));
+    return _oneshot & ((1 << chan) << (TIMER_CHANNEL_NUMOF * tim));
 }
 
 /**
@@ -150,7 +150,7 @@ int timer_init(tim_t tim, unsigned long freq, timer_cb_t cb, void *arg)
 
 int timer_set_absolute(tim_t tim, int channel, unsigned int value)
 {
-    if (channel >= TIMER_CHANNELS) {
+    if (channel >= TIMER_CHANNEL_NUMOF) {
         return -1;
     }
 
@@ -168,7 +168,7 @@ int timer_set_absolute(tim_t tim, int channel, unsigned int value)
 
 int timer_set(tim_t tim, int channel, unsigned int timeout)
 {
-    if (channel >= TIMER_CHANNELS) {
+    if (channel >= TIMER_CHANNEL_NUMOF) {
         return -1;
     }
 
@@ -197,7 +197,7 @@ int timer_set_periodic(tim_t tim, int channel, unsigned int value, uint8_t flags
 {
     int res = 0;
 
-    if (channel >= TIMER_CHANNELS) {
+    if (channel >= TIMER_CHANNEL_NUMOF) {
         return -1;
     }
 
@@ -235,7 +235,7 @@ int timer_set_periodic(tim_t tim, int channel, unsigned int value, uint8_t flags
 
 int timer_clear(tim_t tim, int channel)
 {
-    if (channel >= TIMER_CHANNELS) {
+    if (channel >= TIMER_CHANNEL_NUMOF) {
         return -1;
     }