diff --git a/wled00/fcn_declare.h b/wled00/fcn_declare.h
index 71b00599cd..f856fff97c 100644
--- a/wled00/fcn_declare.h
+++ b/wled00/fcn_declare.h
@@ -324,6 +324,10 @@ class Usermod {
   protected:
     // Shim for oappend(), which used to exist in utils.cpp
     template<typename T> static inline void oappend(const T& t) { oappend_shim->print(t); };
+#ifdef ESP8266
+    // Handle print(PSTR()) or print(SET_F()) without crashing by detecting PROGMEM strings
+    static void oappend(const char* c) { if ((intptr_t) c >= 0x40000000) oappend_shim->print(FPSTR(c)); else oappend_shim->print(c); };
+#endif
 };
 
 class UsermodManager {