diff --git a/src/structures/Constants.sac b/src/structures/Constants.sac
index 9c523f2d..062f4263 100644
--- a/src/structures/Constants.sac
+++ b/src/structures/Constants.sac
@@ -111,7 +111,3 @@ external double maxdouble();
 external double epidouble();
     #pragma linksign[0]
     #pragma linkobj "src/Constants/epidouble.o"
-
-external int randmax();
-    #pragma linksign[0]
-    #pragma linkobj "src/Constants/randmax.o"
diff --git a/src/structures/src/Char/ctype.c b/src/structures/src/Char/ctype.c
index 23c76850..301e5ae3 100644
--- a/src/structures/src/Char/ctype.c
+++ b/src/structures/src/Char/ctype.c
@@ -9,6 +9,7 @@
  *  They may return any non-zero value when true, but a SAC bool is true if 1.
  */
 
+#include <sacinterface.h>
 #include <ctype.h>
 
 typedef unsigned char uchar;
@@ -68,12 +69,12 @@ int SACiscntrl(uchar c)
   return iscntrl(c) != 0;
 }
 
-int SACisascii(int c)
+int SACisascii(sac_int c)
 {
   return c >= 0 && c < 256 && isascii(c) != 0;
 }
 
-int SACtoascii(int c)
+int SACtoascii(sac_int c)
 {
   return toascii(c & 0xFF);
 }
diff --git a/src/structures/src/Constants/maxint.c b/src/structures/src/Constants/maxint.c
index 2078a486..f5080f5a 100644
--- a/src/structures/src/Constants/maxint.c
+++ b/src/structures/src/Constants/maxint.c
@@ -1,7 +1,15 @@
-#include <limits.h>
+#include <sacinterface.h>
 
+#include <stdint.h>
 
-int maxint( void)
+sac_int maxint( void)
 {
-  return( INT_MAX);
+    sac_int num_bits = 8 * sizeof(sac_int);
+    /**
+     * To avoid overflow:
+     * 2^(num_bits - 1) - 1 = 2 * 2^(num_bits - 2) - 1 = 
+     * 2^(num_bits - 2) + (2^(num_bits - 2) - 1)
+     **/
+    sac_int half = (sac_int)1 << (num_bits - 2);
+    return half + (half - 1);
 }
diff --git a/src/structures/src/Constants/minint.c b/src/structures/src/Constants/minint.c
index d369f318..b5127486 100644
--- a/src/structures/src/Constants/minint.c
+++ b/src/structures/src/Constants/minint.c
@@ -1,7 +1,8 @@
+#include <sacinterface.h>
 #include <limits.h>
 
-
-int minint( void)
+sac_int minint( void)
 {
-  return( INT_MIN );
+    sac_int num_bits = 8 * sizeof(sac_int);
+    return -((sac_int)1 << (num_bits - 1));
 }