diff --git a/lib/microTime/src/TimeLib.h b/lib/microTime/src/TimeLib.h
index 45efb398..2e3a7f44 100644
--- a/lib/microTime/src/TimeLib.h
+++ b/lib/microTime/src/TimeLib.h
@@ -154,7 +154,7 @@ time_t now(uint32_t &sysTimeMicros); // return the current time as seconds and
 
 #endif
 #ifdef usePPS
-void SyncToPPS();
+void IRAM_ATTR SyncToPPS();
 #endif
 void setTime(time_t t);
 void setTime(int hr, int min, int sec, int day, int month, int yr);
diff --git a/lib/microTime/src/microTime.cpp b/lib/microTime/src/microTime.cpp
index 4dd745ad..055c8cf7 100644
--- a/lib/microTime/src/microTime.cpp
+++ b/lib/microTime/src/microTime.cpp
@@ -260,7 +260,7 @@ time_t sysUnsyncedTime = 0; // the time sysTime unadjusted by sync
 #endif
 
 #ifdef usePPS
-void SyncToPPS() {
+void IRAM_ATTR SyncToPPS() {
   sysTime++;
   prevMicros = micros();
 }