diff --git a/src/unix/dialup.cpp b/src/unix/dialup.cpp
index 8477a353e2..d6f6e73b24 100644
--- a/src/unix/dialup.cpp
+++ b/src/unix/dialup.cpp
@@ -712,15 +712,15 @@ wxDialUpManagerImpl::CheckIfconfig()
 
 #if defined(__SOLARIS__) || defined (__SUNOS__)
                     // dialup device under SunOS/Solaris
-                    hasModem = strstr(output,"ipdptp") != (char *)NULL;
-                    hasLAN = strstr(output, "hme") != (char *)NULL;
+                    hasModem = strstr(output.fn_str(),"ipdptp") != (char *)NULL;
+                    hasLAN = strstr(output.fn_str(), "hme") != (char *)NULL;
 #elif defined(__LINUX__) || defined (__FREEBSD__)
                     hasModem = strstr(output.fn_str(),"ppp")    // ppp
                         || strstr(output.fn_str(),"sl")  // slip
                         || strstr(output.fn_str(),"pl"); // plip
                     hasLAN = strstr(output.fn_str(), "eth") != NULL;
 #elif defined(__SGI__)  // IRIX
-                    hasModem = strstr(output, "ppp") != NULL; // PPP
+                    hasModem = strstr(output.fn_str(), "ppp") != NULL; // PPP
 #elif defined(__HPUX__)
                     // if could run ifconfig on interface, then it exists
                     hasModem = TRUE;