diff --git a/src/dudley/ddl.h b/src/dudley/ddl.h
index 88b07ade77..711f92f4e9 100644
--- a/src/dudley/ddl.h
+++ b/src/dudley/ddl.h
@@ -286,9 +286,8 @@ typedef struct funcarg {
 
 enum idx_direction
 {
-	IDX_type_none = -1,
-	IDX_type_ascending = 0,
-	IDX_type_descending = 1
+	IDX_type_none = 0,
+	IDX_type_descend = 1
 };
 
 typedef struct dudley_idx {
diff --git a/src/dudley/exe.epp b/src/dudley/exe.epp
index 84e6e1bd47..a8c5144722 100644
--- a/src/dudley/exe.epp
+++ b/src/dudley/exe.epp
@@ -1420,7 +1420,7 @@ static void add_index( DUDLEY_IDX index)
 	X.RDB$SEGMENT_COUNT = index->idx_count;
 	X.RDB$UNIQUE_FLAG = (index->idx_unique) ? TRUE : FALSE;
 	X.RDB$INDEX_INACTIVE = (index->idx_inactive) ? TRUE : FALSE;
-	if (index->idx_type != IDX_type_none) {
+	if (index->idx_type) {
 		X.RDB$INDEX_TYPE = index->idx_type;
 		X.RDB$INDEX_TYPE.NULL = FALSE;
 	}
@@ -3706,9 +3706,7 @@ static void modify_index( DUDLEY_IDX index)
 				X.RDB$INDEX_INACTIVE = (index->idx_inactive) ? TRUE : FALSE;
 				if (index->idx_flags & IDX_unique_flag)
 					X.RDB$UNIQUE_FLAG = (index->idx_unique) ? TRUE : FALSE;
-				if ((index->idx_flags & IDX_type_flag) 
-				&& (index->idx_type != IDX_type_none)) 
-				{
+				if (index->idx_flags & IDX_type_flag) {
 					X.RDB$INDEX_TYPE = index->idx_type;
 					X.RDB$INDEX_TYPE.NULL = FALSE;
 				}
diff --git a/src/dudley/parse.cpp b/src/dudley/parse.cpp
index 99827fdeeb..fd12cda905 100644
--- a/src/dudley/parse.cpp
+++ b/src/dudley/parse.cpp
@@ -1044,7 +1044,7 @@ static void define_index(void)
 	SSHORT count;
 	bool unique = false;
 	bool inactive = false;
-	bool descending = false;
+	idx_direction descending = IDX_type_none;
 
 	index_name = PARSE_symbol(tok_ident);
 	MATCH(KW_FOR);
@@ -1062,9 +1062,9 @@ static void define_index(void)
 		else if (MATCH(KW_INACTIVE))
 			inactive = true;
 		else if (MATCH(KW_ASCENDING))
-			descending = false;
+			descending = IDX_type_none;
 		else if (MATCH(KW_DESCENDING))
-			descending = true;
+			descending = IDX_type_descend;
 		else
 			break;
 	}
@@ -1089,7 +1089,7 @@ static void define_index(void)
 	index->idx_unique = unique;
 	index->idx_description = description;
 	index->idx_inactive = inactive;
-	index->idx_type = IDX_type_none;
+	index->idx_type = descending;
 
 	ptr = &index->idx_field[count];
 
@@ -2542,11 +2542,11 @@ static void modify_index(void)
 			index->idx_flags |= IDX_active_flag;
 		}
 		else if (MATCH(KW_ASCENDING)) {
-			index->idx_type = IDX_type_ascending;
+			index->idx_type = IDX_type_none;
 			index->idx_flags |= IDX_type_flag;
 		}
 		else if (MATCH(KW_DESCENDING)) {
-			index->idx_type = IDX_type_descending;
+			index->idx_type = IDX_type_descend;
 			index->idx_flags |= IDX_type_flag;
 		}
 		else if (KEYWORD(KW_DESCRIPTION)) {
diff --git a/src/dudley/trn.cpp b/src/dudley/trn.cpp
index bf9671f38b..adb559060b 100644
--- a/src/dudley/trn.cpp
+++ b/src/dudley/trn.cpp
@@ -640,7 +640,7 @@ static void add_index( STR dyn, DUDLEY_IDX index)
 	put_symbol(dyn, gds_dyn_rel_name, index->idx_relation);
 	put_number(dyn, gds_dyn_idx_unique, (index->idx_unique) ? TRUE : FALSE);
 	put_number(dyn, gds_dyn_idx_inactive, (index->idx_inactive) ? TRUE : FALSE);
-	if (index->idx_type != IDX_type_none)
+	if (index->idx_type)
 		put_number(dyn, gds_dyn_idx_type, index->idx_type);
 
 	put_text(dyn, gds_dyn_description, index->idx_description);
@@ -1380,7 +1380,7 @@ static void modify_index( STR dyn, DUDLEY_IDX index)
 		put_number(dyn, gds_dyn_idx_inactive,
 				   (index->idx_inactive) ? TRUE : FALSE);
 
-	if ((index->idx_flags & IDX_type_flag) && (index->idx_type != IDX_type_none))
+	if (index->idx_flags & IDX_type_flag)
 		put_number(dyn, gds_dyn_idx_type, index->idx_type);
 
 	if (index->idx_flags & IDX_null_description) {