diff --git a/mongoose.h b/mongoose.h
index 55a828c5..a1d00646 100644
--- a/mongoose.h
+++ b/mongoose.h
@@ -241,6 +241,7 @@ static __inline struct tm *localtime_r(time_t *t, struct tm *tm) {
 #include <stdbool.h>
 #include <stdint.h>
 #include <string.h>
+#include <stdio.h>
 
 #if defined(__GNUC__)
 #include <sys/stat.h>
diff --git a/src/arch_freertos_lwip.h b/src/arch_freertos_lwip.h
index 88d08ff4..de19d9fb 100644
--- a/src/arch_freertos_lwip.h
+++ b/src/arch_freertos_lwip.h
@@ -6,6 +6,7 @@
 #include <stdbool.h>
 #include <stdint.h>
 #include <string.h>
+#include <stdio.h>
 
 #if defined(__GNUC__)
 #include <sys/stat.h>