diff --git a/src/machine/machine_stm32l0x1.go b/src/machine/machine_stm32l0x1.go
index f0d23ca49..292b81f46 100644
--- a/src/machine/machine_stm32l0x1.go
+++ b/src/machine/machine_stm32l0x1.go
@@ -188,8 +188,8 @@ func (t *TIM) enableMainOutput() {
 	// nothing to do - no BDTR register
 }
 
-type arrtype = uint16
-type arrRegType = volatile.Register16
+type arrtype = uint32
+type arrRegType = volatile.Register32
 
 const (
 	ARR_MAX = 0x10000
diff --git a/src/machine/machine_stm32l0x2.go b/src/machine/machine_stm32l0x2.go
index 2a747920b..fe1ba3a22 100644
--- a/src/machine/machine_stm32l0x2.go
+++ b/src/machine/machine_stm32l0x2.go
@@ -245,8 +245,8 @@ func (t *TIM) enableMainOutput() {
 	// nothing to do - no BDTR register
 }
 
-type arrtype = uint16
-type arrRegType = volatile.Register16
+type arrtype = uint32
+type arrRegType = volatile.Register32
 
 const (
 	ARR_MAX = 0x10000