Index: PGConnection.h
==================================================================
--- PGConnection.h
+++ PGConnection.h
@@ -16,14 +16,14 @@
 
 - (void)setParameters: (OFDictionary*)parameters;
 - (OFDictionary*)parameters;
 - (void)connect;
 - (void)reset;
-- (PGResult*)executeCommand: (OFString*)command;
-- (PGResult*)executeCommand: (OFString*)command
+- (PGResult*)executeCommand: (OFConstantString*)command;
+- (PGResult*)executeCommand: (OFConstantString*)command
 		 parameters: (id)firstParameter, ...;
 - (PGconn*)PG_connection;
 - (void)insertRow: (OFDictionary*)row
 	intoTable: (OFString*)table;
 - (void)insertRows: (OFArray*)rows
 	 intoTable: (OFString*)table;
 @end

Index: PGConnection.m
==================================================================
--- PGConnection.m
+++ PGConnection.m
@@ -56,11 +56,11 @@
 - (void)reset
 {
 	PQreset(conn);
 }
 
-- (PGResult*)executeCommand: (OFString*)command
+- (PGResult*)executeCommand: (OFConstantString*)command
 {
 	PGresult *result = PQexec(conn, [command UTF8String]);
 
 	if (PQresultStatus(result) == PGRES_FATAL_ERROR) {
 		PQclear(result);
@@ -75,11 +75,11 @@
 
 	PQclear(result);
 	return nil;
 }
 
-- (PGResult*)executeCommand: (OFString*)command
+- (PGResult*)executeCommand: (OFConstantString*)command
 		 parameters: (id)parameter, ...
 {
 	OFAutoreleasePool *pool = [[OFAutoreleasePool alloc] init];
 	PGresult *result;
 	const char **values;