diff --git a/alloc.c b/alloc.c
index e6759ff..931ed07 100644
--- a/alloc.c
+++ b/alloc.c
@@ -15,7 +15,8 @@ void *tmp;
 tmp = calloc(n, s);
 if (tmp==NULL)
     {
-    fprintf(stderr, "Failure to allocate %d objects of %d bytes ", n, s); 
+    fprintf(stderr, "Failure to allocate %lu objects of %lu bytes ", 
+	    (unsigned long) n, (unsigned long) s); 
     fprintf(stderr, "on line %d of %s\n", l, f);
     fprintf(stderr, "Emergency stop.\n");
     exit(1);
diff --git a/gambit.c b/gambit.c
index 2a8d231..3e3f1d5 100644
--- a/gambit.c
+++ b/gambit.c
@@ -4,6 +4,7 @@
  */
 
 #include <stdio.h>
+#include <stdlib.h>
 
 #include "rat.h"
 #include "treedef.h"
diff --git a/interface.c b/interface.c
index b55256b..b9ed8b8 100644
--- a/interface.c
+++ b/interface.c
@@ -4,6 +4,7 @@
  */
 
 #include <stdio.h>
+#include <stdlib.h>
 
 #include "rat.h"
 #include "treedef.h"    /* PLAYERS              */
diff --git a/leaves.c b/leaves.c
index 0cbdb32..3cd2355 100644
--- a/leaves.c
+++ b/leaves.c
@@ -14,6 +14,7 @@
 #include "leaves.h"
 
 /* test if input properly processed by generating what should be an echo */
+#ifdef UNUSED
 static void testreadequil (int docuseed)
 {
     printf("BEQ>%4d<1>", docuseed);
@@ -21,6 +22,7 @@ static void testreadequil (int docuseed)
     printf(" <2>");
     outbehavstrat(2, realplan[2], 1);
 }
+#endif  /* UNUSED */
 
 void leavesfrominput (void)
 {
@@ -104,7 +106,7 @@ void outleavesreached (int docuseed)
 	if ( reachprob.num )  /* nonzero probability of reaching leaf	*/
 	    {
 	    rattoa(reachprob, s); 
-	    printf(" %d~%s", o - outcomes, s) ;
+	    printf(" %ld~%s", o - outcomes, s) ;
 	    }
 	}
     printf("\n") ;
diff --git a/main.c b/main.c
index b28b688..d308b3d 100644
--- a/main.c
+++ b/main.c
@@ -118,13 +118,13 @@ int stopwatch(Bool bprint)
 void infotree()
 {
     int pl;
-    printf("\nGame tree has %d nodes, ", lastnode - root);
-    printf("of which %d are terminal nodes.\n", lastoutcome - outcomes);
+    printf("\nGame tree has %ld nodes, ", lastnode - root);
+    printf("of which %ld are terminal nodes.\n", lastoutcome - outcomes);
     for (pl = 0; pl < PLAYERS; pl++)
 	{
 	printf("    Player %d has ", pl);
-	printf("%3d information sets, ", firstiset[pl+1] - firstiset[pl]);
-	printf("%3d moves in total\n", firstmove[pl+1] - firstmove[pl] - 1); 
+	printf("%3ld information sets, ", firstiset[pl+1] - firstiset[pl]);
+	printf("%3ld moves in total\n", firstmove[pl+1] - firstmove[pl] - 1); 
 	}
 }
 
@@ -324,7 +324,7 @@ int main(int argc, char *argv[])
     int multipriors = 0;         /* parameter for    -M option  */
     int seed  = 0;      /* payoff seed for bintree  (-s option) */
     int newpayoffs = 0; /* number of payoffs to be replaced (-p)*/
-    int *newp1, *newp2; /* arrays for entering new payoffs      */
+    int *newp1 = 0, *newp2 = 0; /* arrays for entering new payoffs      */
 
     /* whichform currently not used (later for RSF)             */
     int whichform = 0;  /* 0: SF, 1: NF, 2: RSF                 */
diff --git a/mp.c b/mp.c
index f344039..3d0d0ab 100644
--- a/mp.c
+++ b/mp.c
@@ -118,12 +118,12 @@ void prat(char name[],mp Nt,mp Dt)  /*print the long precision rational Nt/Dt  *
 	long i;
 	printf("%s",name);
 	if (sign(Nt)==NEG) printf("-");
-	printf("%u",Nt[length(Nt)-1]);
+	printf("%ld",Nt[length(Nt)-1]);
 	for (i=length(Nt)-2;i>=1;i--) printf(FORMAT,Nt[i]);
 	if( !(Dt[0]==2 && Dt[1]==1))  /* rational */
 	     { printf("/");
 	       if (sign(Dt)==NEG) printf("-");
-	       printf("%u",Dt[length(Dt)-1]);
+	       printf("%ld",Dt[length(Dt)-1]);
 	       for (i=length(Dt)-2;i>=1;i--) printf(FORMAT,Dt[i]);
 	      }
 	printf(" ");
@@ -146,7 +146,7 @@ void pmp(char name[],mp a)  /*print the long precision integer a*/
 	long i;
 	printf("%s",name);
 	if (sign(a)==NEG) printf("-");
-	printf("%u",a[length(a)-1]);
+	printf("%ld",a[length(a)-1]);
 	for (i=length(a)-2;i>=1;i--) printf(FORMAT,a[i]);
 }
 
@@ -157,7 +157,7 @@ int mptoa(mp x, char s[])
 int i, pos=0;
 if (sign(x)==NEG) 
     pos = sprintf(s, "-");
-pos += sprintf(&s[pos], "%u", x[length(x)-1] );
+pos += sprintf(&s[pos], "%ld", x[length(x)-1] );
 for (i=length(x)-2; i>=1; i--) 
     pos += sprintf(&s[pos], FORMAT, x[i]);
 return pos;
@@ -197,7 +197,7 @@ void gcd(mp u, mp v)
   bigu:
     if(zero(v))
         return;
-    if ((i=length(u))<maxsplen || i==maxsplen && u[maxsplen-1]<maxspval)
+    if ((i=length(u))<maxsplen || (i==maxsplen && u[maxsplen-1]<maxspval))
         goto quickfinish;
     divint(u,v,r);
     normalize(u);
@@ -208,7 +208,7 @@ void gcd(mp u, mp v)
         copy(u,v);
         return;
         }
-    if ((i=length(v))<maxsplen || i==maxsplen && v[maxsplen-1]<maxspval)
+    if ((i=length(v))<maxsplen || (i==maxsplen && v[maxsplen-1]<maxspval))
         goto quickfinish;
     divint (v,u,r);
     normalize(v);
@@ -576,7 +576,7 @@ void divint(mp a, mp b, mp c )
  
 void digits_overflow()
 {
-  printf("Overflow at digits=%d\n",DIG2DEC(digits));
+  printf("Overflow at digits=%ld\n",DIG2DEC(digits));
   exit(1);
 }
 
@@ -588,7 +588,7 @@ void digits_overflow()
 /***************************************************************/
 
 
-linrat(Na,Da,ka,Nb,Db,kb,Nc,Dc) 
+void linrat(Na,Da,ka,Nb,Db,kb,Nc,Dc) 
 	/* computes Nc/Dc = ka*Na/Da  +kb* Nb/Db 
 	   and reduces answer by gcd(Nc,Dc) */
 mp Na,Da,Nb,Db,Nc,Dc;
@@ -603,7 +603,7 @@ reduce(Nc,Dc);
 }
 
 
-divrat(Na,Da,Nb,Db,Nc,Dc) 
+void divrat(Na,Da,Nb,Db,Nc,Dc) 
 	/* computes Nc/Dc = (Na/Da)  / ( Nb/Db )
 	   and reduces answer by gcd(Nc,Dc) */
 mp Na,Da,Nb,Db,Nc,Dc;
@@ -614,7 +614,7 @@ reduce(Nc,Dc);
 }
  
 
-mulrat(Na,Da,Nb,Db,Nc,Dc) 
+void mulrat(Na,Da,Nb,Db,Nc,Dc) 
 	/* computes Nc/Dc = Na/Da  * Nb/Db
 	   and reduces answer by gcd(Nc,Dc) */
 mp Na,Da,Nb,Db,Nc,Dc;
diff --git a/mp.h b/mp.h
index 98cfd28..6f092fd 100644
--- a/mp.h
+++ b/mp.h
@@ -16,7 +16,7 @@
 /***********************************************/
 #ifndef B64
 /*32 bit machines */
-#define FORMAT "%4.4u"
+#define FORMAT "%4.4ld"
 #define MAXD 2147483647L
 #define BASE 10000L
 #define BASE_DIG 4
diff --git a/rsf.c b/rsf.c
index 9aca88f..36861e0 100644
--- a/rsf.c
+++ b/rsf.c
@@ -34,7 +34,7 @@ void genredsf(int pl)
     int i, j;       /* row, column counters */
     int cdim;       /* dimension of c-matrix, = no. redundant vars          */
     int drow;       /* last filled row of d-matrix for irredundant vars     */
-    Iset h, lasthinc;
+    Iset h = 0, lasthinc = 0;
     Move seq;
     /* inverse of matrix of dependent variables, local      */
     int ** depvarinv;
diff --git a/treedef.c b/treedef.c
index 4403b23..cc01305 100644
--- a/treedef.c
+++ b/treedef.c
@@ -91,9 +91,9 @@ Bool genseqin(void)
 	    /* tree is not topologically sorted     */
 	    {
 	    isnotok = 1;
-	    printf("tree not topologically sorted: father %d ", 
+	    printf("tree not topologically sorted: father %ld ", 
 		    u->father - nodes);
-	    printf("is larger than node %d itself.\n", u - nodes);
+	    printf("is larger than node %ld itself.\n", u - nodes);
 	    }
     
 	/* update sequence triple, new only for move leading to  u  */
@@ -113,10 +113,10 @@ Bool genseqin(void)
 		{
 		isnotok = 1;
 		/* need output routines for isets, moves, later         */
-		printf("imperfect recall in info set no. %d ", h-isets);
+		printf("imperfect recall in info set no. %ld ", h-isets);
 		printf("named %s\n", h->name);
-		printf("different sequences no. %d,", seq-moves);
-		printf(" %d\n", h->seqin-moves);
+		printf("different sequences no. %ld,", seq-moves);
+		printf(" %ld\n", h->seqin-moves);
 		}
 	    }       /* end of "u decision node"     */
 	}           /* end of "for all nodes u"     */
@@ -184,7 +184,7 @@ int movetoa (Move c, int pl, char *s)
 	return sprintf(s, "*");
     if (c == firstmove[pl])
 	return sprintf(s, "()");
-    return sprintf(s, "%s%d", c->atiset->name, c - c->atiset->move0);
+    return sprintf(s, "%s%ld", c->atiset->name, c - c->atiset->move0);
 }       /* end of  int movetoa (c, pl, *s)      */
 
 int seqtoa (Move seq, int pl, char *s)
diff --git a/treegen.c b/treegen.c
index 3155305..9f71700 100644
--- a/treegen.c
+++ b/treegen.c
@@ -116,7 +116,7 @@ void createbintree (int levels, int seed)
         }
     /* consistency check    */
     if (currout != lastoutcome)
-        printf("wrong number %d of outcomes!!!\n", currout-outcomes );
+        printf("wrong number %ld of outcomes!!!\n", currout-outcomes );
 }       /* end of createbintree(levels, seed)   */