expExpressionConf, expValue: isspace cannot take a char argument.
diff --git a/agent/mibgroup/disman/expr/expExpressionConf.c b/agent/mibgroup/disman/expr/expExpressionConf.c
index 743ef9d..61744e1 100644
--- a/agent/mibgroup/disman/expr/expExpressionConf.c
+++ b/agent/mibgroup/disman/expr/expExpressionConf.c
@@ -134,7 +134,7 @@
          * object name into the expression field...
          */
         /*   XXX - TODO - Handle string literals */
-        if (!isalpha(*cp)) {
+        if (!isalpha(*cp & 0xFF)) {
            *cp2++ = *cp++;
            continue;
         }
diff --git a/agent/mibgroup/disman/expr/expValue.c b/agent/mibgroup/disman/expr/expValue.c
index 46638f2..eeff402 100644
--- a/agent/mibgroup/disman/expr/expValue.c
+++ b/agent/mibgroup/disman/expr/expValue.c
@@ -230,7 +230,7 @@
 
     n = atoi(start);
     for (cp=start; *cp; cp++)
-        if (!isdigit(*cp))
+        if (!isdigit(*cp & 0xFF))
             break;
     *end = cp;
     return n;
@@ -565,7 +565,7 @@
             break;
 
         default:
-            if (isalpha( *cp1 )) {
+            if (isalpha( *cp1 & 0xFF )) {
                 /*
                  * Unrecognised function call ?
                  */
@@ -576,7 +576,7 @@
                 var->data = (void *)(cp1 - exprRaw);
                 return var;
             }
-            else if (!isspace( *cp1 )) {
+            else if (!isspace( *cp1 & 0xFF )) {
                 /*
                  * Unrecognised operator ?
                  */