diff --git a/source/interfaces/retro-compiler.c b/source/interfaces/retro-compiler.c
index b545dc2..347c0ed 100644
--- a/source/interfaces/retro-compiler.c
+++ b/source/interfaces/retro-compiler.c
@@ -19,6 +19,7 @@
 #include <unistd.h>
 #include <string.h>
 #include <sys/stat.h>
+#include <limits.h>
 
 #ifndef BIT64
 #define CELL int32_t
diff --git a/source/interfaces/retro-runtime.c b/source/interfaces/retro-runtime.c
index 1429958..f36622b 100644
--- a/source/interfaces/retro-runtime.c
+++ b/source/interfaces/retro-runtime.c
@@ -32,6 +32,7 @@
 #include <sys/wait.h>
 #include <time.h>
 #include <unistd.h>
+#include <limits.h>
 
 
 /*---------------------------------------------------------------------
diff --git a/source/interfaces/retro-unix.c b/source/interfaces/retro-unix.c
index ec184cc..9e67576 100644
--- a/source/interfaces/retro-unix.c
+++ b/source/interfaces/retro-unix.c
@@ -32,7 +32,7 @@
 #include <sys/wait.h>
 #include <time.h>
 #include <unistd.h>
-
+#include <limits.h>
 
 /*---------------------------------------------------------------------
   Configuration