diff --git a/os/common/ports/ARM/chcore.h b/os/common/ports/ARM/chcore.h
index cceb70147..718b6f27e 100644
--- a/os/common/ports/ARM/chcore.h
+++ b/os/common/ports/ARM/chcore.h
@@ -162,16 +162,6 @@
 /* Module pre-compile time settings.                                         */
 /*===========================================================================*/
 
-/**
- * @brief   Enables an alternative timer implementation.
- * @details Usually the port uses a timer interface defined in the file
- *          @p chcore_timer.h, if this option is enabled then the file
- *          @p chcore_timer_alt.h is included instead.
- */
-#if !defined(PORT_USE_ALT_TIMER)
-#define PORT_USE_ALT_TIMER              FALSE
-#endif
-
 /**
  * @brief   Stack size for the system idle thread.
  * @details This size depends on the idle thread implementation, usually
diff --git a/os/common/ports/ARMv6-M-RP2/chcore.h b/os/common/ports/ARMv6-M-RP2/chcore.h
index 0dc7c2e14..566e2e7c2 100644
--- a/os/common/ports/ARMv6-M-RP2/chcore.h
+++ b/os/common/ports/ARMv6-M-RP2/chcore.h
@@ -174,16 +174,6 @@
 #define PORT_INT_REQUIRED_STACK         64
 #endif
 
-/**
- * @brief   Enables an alternative timer implementation.
- * @details Usually the port uses a timer interface defined in the file
- *          @p chcore_timer.h, if this option is enabled then the file
- *          @p chcore_timer_alt.h is included instead.
- */
-#if !defined(PORT_USE_ALT_TIMER)
-#define PORT_USE_ALT_TIMER              FALSE
-#endif
-
 /**
  * @brief   Enables the use of the WFI instruction in the idle thread loop.
  */
diff --git a/os/common/ports/ARMv6-M/chcore.h b/os/common/ports/ARMv6-M/chcore.h
index dbc89d04e..7e49ff15e 100644
--- a/os/common/ports/ARMv6-M/chcore.h
+++ b/os/common/ports/ARMv6-M/chcore.h
@@ -156,16 +156,6 @@
 #define PORT_INT_REQUIRED_STACK         64
 #endif
 
-/**
- * @brief   Enables an alternative timer implementation.
- * @details Usually the port uses a timer interface defined in the file
- *          @p chcore_timer.h, if this option is enabled then the file
- *          @p chcore_timer_alt.h is included instead.
- */
-#if !defined(PORT_USE_ALT_TIMER)
-#define PORT_USE_ALT_TIMER              FALSE
-#endif
-
 /**
  * @brief   Enables the use of the WFI instruction in the idle thread loop.
  */
diff --git a/os/common/ports/ARMv7-M/chcore.h b/os/common/ports/ARMv7-M/chcore.h
index 5f17a71f3..293dc5f51 100644
--- a/os/common/ports/ARMv7-M/chcore.h
+++ b/os/common/ports/ARMv7-M/chcore.h
@@ -170,17 +170,6 @@
 #define PORT_INT_REQUIRED_STACK         64
 #endif
 
-
-/**
- * @brief   Enables an alternative timer implementation.
- * @details Usually the port uses a timer interface defined in the file
- *          @p chcore_timer.h, if this option is enabled then the file
- *          @p chcore_timer_alt.h is included instead.
- */
-#if !defined(PORT_USE_ALT_TIMER)
-#define PORT_USE_ALT_TIMER              FALSE
-#endif
-
 /**
  * @brief   Enables the use of the WFI instruction in the idle thread loop.
  */
diff --git a/os/common/ports/ARMv8-M-ML-TZ/chcore.h b/os/common/ports/ARMv8-M-ML-TZ/chcore.h
index b853f0e85..723159a77 100644
--- a/os/common/ports/ARMv8-M-ML-TZ/chcore.h
+++ b/os/common/ports/ARMv8-M-ML-TZ/chcore.h
@@ -174,16 +174,6 @@
 #define PORT_SWITCHED_REGIONS_NUMBER    0
 #endif
 
-/**
- * @brief   Enables an alternative timer implementation.
- * @details Usually the port uses a timer interface defined in the file
- *          @p chcore_timer.h, if this option is enabled then the file
- *          @p chcore_timer_alt.h is included instead.
- */
-#if !defined(PORT_USE_ALT_TIMER)
-#define PORT_USE_ALT_TIMER              FALSE
-#endif
-
 /**
  * @brief   Stack size for the system idle thread.
  * @details This size depends on the idle thread implementation, usually
diff --git a/os/common/ports/ARMv8-M-ML/chcore.h b/os/common/ports/ARMv8-M-ML/chcore.h
index b6ad4730d..423543706 100644
--- a/os/common/ports/ARMv8-M-ML/chcore.h
+++ b/os/common/ports/ARMv8-M-ML/chcore.h
@@ -131,17 +131,6 @@
 #define PORT_INT_REQUIRED_STACK         64
 #endif
 
-
-/**
- * @brief   Enables an alternative timer implementation.
- * @details Usually the port uses a timer interface defined in the file
- *          @p chcore_timer.h, if this option is enabled then the file
- *          @p chcore_timer_alt.h is included instead.
- */
-#if !defined(PORT_USE_ALT_TIMER)
-#define PORT_USE_ALT_TIMER              FALSE
-#endif
-
 /**
  * @brief   Enables the use of the WFI instruction in the idle thread loop.
  */
diff --git a/os/common/ports/AVR/chcore.h b/os/common/ports/AVR/chcore.h
index 19952cda8..901fd3d59 100644
--- a/os/common/ports/AVR/chcore.h
+++ b/os/common/ports/AVR/chcore.h
@@ -128,16 +128,6 @@ extern bool __avr_in_isr;
 #define PORT_INT_REQUIRED_STACK         32
 #endif
 
-/**
- * @brief   Enables an alternative timer implementation.
- * @details Usually the port uses a timer interface defined in the file
- *          @p chcore_timer.h, if this option is enabled then the file
- *          @p chcore_timer_alt.h is included instead.
- */
-#if !defined(PORT_USE_ALT_TIMER) || defined(__DOXYGEN__)
-#define PORT_USE_ALT_TIMER              FALSE
-#endif
-
 /**
  * @brief   Enables a "wait for interrupt" instruction in the idle loop.
  */
diff --git a/os/common/ports/SIMIA32/chcore.h b/os/common/ports/SIMIA32/chcore.h
index 286160ddd..02e939666 100644
--- a/os/common/ports/SIMIA32/chcore.h
+++ b/os/common/ports/SIMIA32/chcore.h
@@ -113,16 +113,6 @@
 #define PORT_INT_REQUIRED_STACK         16384
 #endif
 
-/**
- * @brief   Enables an alternative timer implementation.
- * @details Usually the port uses a timer interface defined in the file
- *          @p chcore_timer.h, if this option is enabled then the file
- *          @p chcore_timer_alt.h is included instead.
- */
-#if !defined(PORT_USE_ALT_TIMER) || defined(__DOXYGEN__)
-#define PORT_USE_ALT_TIMER              FALSE
-#endif
-
 /*===========================================================================*/
 /* Derived constants and error checks.                                       */
 /*===========================================================================*/
diff --git a/os/common/ports/e200/chcore.h b/os/common/ports/e200/chcore.h
index ddf6eb5b0..bab4a04c2 100644
--- a/os/common/ports/e200/chcore.h
+++ b/os/common/ports/e200/chcore.h
@@ -144,16 +144,6 @@
 #define PORT_INT_REQUIRED_STACK         256
 #endif
 
-/**
- * @brief   Enables an alternative timer implementation.
- * @details Usually the port uses a timer interface defined in the file
- *          @p chcore_timer.h, if this option is enabled then the file
- *          @p chcore_timer_alt.h is included instead.
- */
-#if !defined(PORT_USE_ALT_TIMER) || defined(__DOXYGEN__)
-#define PORT_USE_ALT_TIMER              FALSE
-#endif
-
 /**
  * @brief   Use VLE instruction set.
  * @note    This parameter is usually set in the Makefile.
diff --git a/os/common/ports/templates/chcore.h b/os/common/ports/templates/chcore.h
index 7f54c98b7..f473c8e4e 100644
--- a/os/common/ports/templates/chcore.h
+++ b/os/common/ports/templates/chcore.h
@@ -120,16 +120,6 @@
 #define PORT_INT_REQUIRED_STACK         256
 #endif
 
-/**
- * @brief   Enables an alternative timer implementation.
- * @details Usually the port uses a timer interface defined in the file
- *          @p chcore_timer.h, if this option is enabled then the file
- *          @p chcore_timer_alt.h is included instead.
- */
-#if !defined(PORT_USE_ALT_TIMER) || defined(__DOXYGEN__)
-#define PORT_USE_ALT_TIMER              FALSE
-#endif
-
 /**
  * @brief   Enables a "wait for interrupt" instruction in the idle loop.
  */