diff --git a/src/lib-sieve/plugins/comparator-i-ascii-numeric/ext-cmp-i-ascii-numeric.c b/src/lib-sieve/plugins/comparator-i-ascii-numeric/ext-cmp-i-ascii-numeric.c
index 760175c9976219bbfc3c2e33c5f78acacf7ec508..35de40f837a68cbe46bec0fde1fbeadf5e4c32c6 100644
--- a/src/lib-sieve/plugins/comparator-i-ascii-numeric/ext-cmp-i-ascii-numeric.c
+++ b/src/lib-sieve/plugins/comparator-i-ascii-numeric/ext-cmp-i-ascii-numeric.c
@@ -107,7 +107,7 @@ static int cmp_i_ascii_numeric_compare
 		kp++;
 
 	while ( vp < vend && kp < kend ) {
-		if ( !isdigit(*vp) || !isdigit(*kp) ) 
+		if ( !i_isdigit(*vp) || !i_isdigit(*kp) ) 
 			break;
 
 		if ( *vp != *kp ) 
@@ -117,12 +117,12 @@ static int cmp_i_ascii_numeric_compare
 		kp++;	
 	}
 
-	if ( vp == vend || !isdigit(*vp) ) {
-		if ( kp == kend || !isdigit(*kp) ) 
+	if ( vp == vend || !i_isdigit(*vp) ) {
+		if ( kp == kend || !i_isdigit(*kp) ) 
 			return 0;
 		else	
 			return -1;
-	} else if ( kp == kend || !isdigit(*kp) )  
+	} else if ( kp == kend || !i_isdigit(*kp) )  
 		return 1;
 		
 	return (*vp > *kp);
diff --git a/src/lib-sieve/plugins/variables/ext-variables-name.c b/src/lib-sieve/plugins/variables/ext-variables-name.c
index e4b2675fbb3562eed3eff14a6767859ecdc6e8a5..ac9f00920f217546e80d0c12e4ec146c570953c8 100644
--- a/src/lib-sieve/plugins/variables/ext-variables-name.c
+++ b/src/lib-sieve/plugins/variables/ext-variables-name.c
@@ -32,23 +32,23 @@ int ext_variable_name_parse
 		}
 
 		/* Identifier */
-		if ( *p == '_' || isalpha(*p) ) {
+		if ( *p == '_' || i_isalpha(*p) ) {
 			cur_element->num_variable = -1;
 			str_truncate(cur_ident, 0);
 			str_append_c(cur_ident, *p);
 			p++;
 		
-			while ( p < strend && (*p == '_' || isalnum(*p)) ) {
+			while ( p < strend && (*p == '_' || i_isalnum(*p)) ) {
 				str_append_c(cur_ident, *p);
 				p++;
 			}
 		
 		/* Num-variable */
-		} else if ( isdigit(*p) ) {
+		} else if ( i_isdigit(*p) ) {
 			cur_element->num_variable = *p - '0';
 			p++;
 			
-			while ( p < strend && isdigit(*p) ) {
+			while ( p < strend && i_isdigit(*p) ) {
 				cur_element->num_variable = cur_element->num_variable*10 + (*p - '0');
 				p++;
 			}