diff --git a/contrib/ltree/crc32.c b/contrib/ltree/crc32.c
index bdfba6a332343d2820a0f4b5998f47b4d3b26ab1..0e04bdb1b0a12772ceff8c403c8522cb485581f1 100644
--- a/contrib/ltree/crc32.c
+++ b/contrib/ltree/crc32.c
@@ -105,6 +105,6 @@ crc32_sz(char *buf, int size)
 	len = 0;
 	nr = size;
 	for (len += nr, p = buf; nr--; ++p)
-		_CRC32_(crc, TOLOWER(*p));
+		_CRC32_(crc, TOLOWER((unsigned int)*p));
 	return ~crc;
 }
diff --git a/contrib/ltree/ltree.h b/contrib/ltree/ltree.h
index 22134befafcee93e9a9e10b446f59ce9db067b9e..a53684370aeabe870e39dea5c75863a2e18a0e36 100644
--- a/contrib/ltree/ltree.h
+++ b/contrib/ltree/ltree.h
@@ -83,7 +83,7 @@ typedef struct {
 #ifndef abs
 #define abs(a)                  ((a) <  (0) ? -(a) : (a))
 #endif
-#define ISALNUM(x)	( isalnum(x) || (x) == '_' )
+#define ISALNUM(x)	( isalnum((unsigned int)(x)) || (x) == '_' )
 
 /* full text query */
 
diff --git a/contrib/ltree/ltree_io.c b/contrib/ltree/ltree_io.c
index 0315dca06b2b359b9eac8f379983ec5ce3c426db..2f9e9ed3adf5e313818df6dcf5492c3225b1741e 100644
--- a/contrib/ltree/ltree_io.c
+++ b/contrib/ltree/ltree_io.c
@@ -18,7 +18,7 @@ PG_FUNCTION_INFO_V1(lquery_out);
 Datum lquery_out(PG_FUNCTION_ARGS);
 
 
-#define UNCHAR elog(ERROR,"Syntax error in position %d near '%c'", ptr-buf, *ptr)
+#define UNCHAR elog(ERROR,"Syntax error in position %d near '%c'", (int)(ptr-buf), *ptr)
 
 typedef struct {
 	char* 	start;
@@ -60,7 +60,7 @@ ltree_in(PG_FUNCTION_ARGS) {
 				lptr->len = ptr - lptr->start;
 				if ( lptr->len > 255 ) 
 					elog(ERROR,"Name of level is too long (%d, must be < 256) in position %d", 
-						lptr->len, lptr->start - buf);
+						lptr->len, (int)(lptr->start - buf));
 				totallen += MAXALIGN(lptr->len + LEVEL_HDRSIZE);
 				lptr++;
 				state = LTPRS_WAITNAME;
@@ -75,7 +75,7 @@ ltree_in(PG_FUNCTION_ARGS) {
 		lptr->len = ptr - lptr->start;
 		if ( lptr->len > 255 ) 
 			elog(ERROR,"Name of level is too long (%d, must be < 256) in position %d", 
-				lptr->len, lptr->start - buf);
+				lptr->len, (int)(lptr->start - buf));
 		totallen += MAXALIGN(lptr->len + LEVEL_HDRSIZE);
 		lptr++;
 	} else if ( ! (state == LTPRS_WAITNAME && lptr == list) )
@@ -214,7 +214,7 @@ lquery_in(PG_FUNCTION_ARGS) {
 					( ( lptr->flag & LVAR_ANYEND ) ? 1 : 0 );
 				if ( lptr->len > 255 ) 
 					elog(ERROR,"Name of level is too long (%d, must be < 256) in position %d", 
-						lptr->len, lptr->start - buf);
+						lptr->len, (int)(lptr->start - buf));
 				state = LQPRS_WAITVAR;
 			} else if ( *ptr == '.' ) {
 				lptr->len = ptr - lptr->start - 
@@ -223,7 +223,7 @@ lquery_in(PG_FUNCTION_ARGS) {
 					( ( lptr->flag & LVAR_ANYEND ) ? 1 : 0 );
 				if ( lptr->len > 255 ) 
 					elog(ERROR,"Name of level is too long (%d, must be < 256) in position %d", 
-						lptr->len, lptr->start - buf);
+						lptr->len, (int)(lptr->start - buf));
 				state = LQPRS_WAITLEVEL;
 				curqlevel = NEXTLEV(curqlevel);
 			} else if ( ISALNUM(*ptr) ) {
@@ -244,13 +244,13 @@ lquery_in(PG_FUNCTION_ARGS) {
 		} else if ( state == LQPRS_WAITFNUM ) {
 			if ( *ptr == ',' ) {
 				state = LQPRS_WAITSNUM; 
-			} else if ( isdigit(*ptr) ) {
+			} else if ( isdigit((unsigned int)*ptr) ) {
 				curqlevel->low = atoi( ptr );
 				state = LQPRS_WAITND;
 			} else
 				UNCHAR; 
 		} else if ( state == LQPRS_WAITSNUM ) {
-			if ( isdigit(*ptr) ) {
+			if ( isdigit((unsigned int)*ptr) ) {
 				curqlevel->high = atoi( ptr );
 				state =  LQPRS_WAITCLOSE;
 			} else if ( *ptr == '}' ) {
@@ -261,7 +261,7 @@ lquery_in(PG_FUNCTION_ARGS) {
 		} else if ( state == LQPRS_WAITCLOSE ) {
 			if ( *ptr == '}' )
 				state = LQPRS_WAITEND;
-			else if ( !isdigit(*ptr) )
+			else if ( !isdigit((unsigned int)*ptr) )
 				UNCHAR;
 		} else if ( state == LQPRS_WAITND ) { 
 			if ( *ptr == '}' ) {
@@ -269,7 +269,7 @@ lquery_in(PG_FUNCTION_ARGS) {
 				state = LQPRS_WAITEND;
 			} else if ( *ptr == ',' )
 				state = LQPRS_WAITSNUM;
-			else if ( !isdigit(*ptr) )
+			else if ( !isdigit((unsigned int)*ptr) )
 				UNCHAR;
 		} else if ( state == LQPRS_WAITEND ) {
 			if ( *ptr == '.' ) {
@@ -293,7 +293,7 @@ lquery_in(PG_FUNCTION_ARGS) {
 			elog(ERROR,"Unexpected end of line");
 		if ( lptr->len > 255 ) 
 			elog(ERROR,"Name of level is too long (%d, must be < 256) in position %d", 
-				lptr->len, lptr->start - buf);
+				lptr->len, (int)(lptr->start - buf));
 	} else if ( state == LQPRS_WAITOPEN ) {
 		curqlevel->high = 0xffff;
 	} else if ( state != LQPRS_WAITEND ) 
diff --git a/contrib/ltree/ltxtquery_io.c b/contrib/ltree/ltxtquery_io.c
index e70d643b8551512a0ec96d9e3f3111369a911a64..e056b84bc0fbfbf991427fa4d56f640f411ec69f 100644
--- a/contrib/ltree/ltxtquery_io.c
+++ b/contrib/ltree/ltxtquery_io.c
@@ -76,7 +76,7 @@ gettoken_query(QPRS_STATE * state, int4 *val, int4 *lenval, char **strval, uint1
 					*strval = state->buf;
 					*lenval = 1;
 					*flag = 0;
-				} else if ( !isspace(*(state->buf)) )
+				} else if ( !isspace((unsigned int)*(state->buf)) )
 					elog(ERROR,"Operand syntax error");
 				break;
 			case INOPERAND: