diff --git a/src/displayapp/DisplayApp.cpp b/src/displayapp/DisplayApp.cpp
index 85c6da3e..4afcd8dc 100644
--- a/src/displayapp/DisplayApp.cpp
+++ b/src/displayapp/DisplayApp.cpp
@@ -55,7 +55,7 @@ using namespace Pinetime::Applications;
 using namespace Pinetime::Applications::Display;
 
 namespace {
-  static inline bool in_isr(void) {
+  inline bool in_isr() {
     return (SCB->ICSR & SCB_ICSR_VECTACTIVE_Msk) != 0;
   }
 }
diff --git a/src/systemtask/SystemTask.cpp b/src/systemtask/SystemTask.cpp
index 1c871fd2..ef631af7 100644
--- a/src/systemtask/SystemTask.cpp
+++ b/src/systemtask/SystemTask.cpp
@@ -22,7 +22,7 @@
 using namespace Pinetime::System;
 
 namespace {
-  static inline bool in_isr(void) {
+  inline bool in_isr() {
     return (SCB->ICSR & SCB_ICSR_VECTACTIVE_Msk) != 0;
   }
 }