diff --git a/src/unix/dialup.cpp b/src/unix/dialup.cpp
index ebd8d41fd8..b9f18e41df 100644
--- a/src/unix/dialup.cpp
+++ b/src/unix/dialup.cpp
@@ -726,7 +726,7 @@ wxDialUpManagerImpl::CheckIfconfig()
                         || 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;