diff --git a/sim/common/callback.c b/sim/common/callback.c
index 105488db262..ed4d51d8d39 100644
--- a/sim/common/callback.c
+++ b/sim/common/callback.c
@@ -29,6 +29,7 @@
 #include <limits.h>
 #include <signal.h>
 #include <stdarg.h>
+#include <stdint.h>
 #include <stdio.h>
 #include <stdlib.h>
 #include <string.h>
diff --git a/sim/common/sim-io.c b/sim/common/sim-io.c
index a278d6ec127..8c40f7a0e73 100644
--- a/sim/common/sim-io.c
+++ b/sim/common/sim-io.c
@@ -27,6 +27,7 @@
 #include <fcntl.h>
 #endif
 #include <stdarg.h>
+#include <stdint.h>
 #include <stdlib.h>
 #if HAVE_UNISTD_H
 #include <unistd.h>
diff --git a/sim/common/sim-io.h b/sim/common/sim-io.h
index c88adcde0f7..2fc22f332cc 100644
--- a/sim/common/sim-io.h
+++ b/sim/common/sim-io.h
@@ -24,6 +24,7 @@
 #define SIM_IO_H
 
 #include <stdarg.h>
+#include <stdint.h>
 #include <sys/stat.h>
 #include <sys/types.h>