diff --git a/src/iosacl/iosacl.cpp b/src/iosacl/iosacl.cpp
index f7afeeb13..d9d884fcd 100644
--- a/src/iosacl/iosacl.cpp
+++ b/src/iosacl/iosacl.cpp
@@ -75,7 +75,7 @@ class UpgradePredicate: public XMLTools::UpgradePredicate
     public:
     virtual bool operator()(const string &msg) const 
     { 
-        msg.size();  // to make compiler happy about unused parameter
+        (void)msg.size();  // to make compiler happy about unused parameter
 	cout << "Data file has been created in the old version of Firewall Builder.\nLoad it in the GUI to convert it to the new version." << endl;
 	return false;
     }
diff --git a/src/junosacl/junosacl.cpp b/src/junosacl/junosacl.cpp
index a3072919c..827df49c9 100644
--- a/src/junosacl/junosacl.cpp
+++ b/src/junosacl/junosacl.cpp
@@ -75,7 +75,7 @@ class UpgradePredicate: public XMLTools::UpgradePredicate
     public:
     virtual bool operator()(const string &msg) const 
     { 
-        msg.size();  // to make compiler happy about unused parameter
+        (void)msg.size();  // to make compiler happy about unused parameter
 	cout << "Data file has been created in the old version of Firewall Builder.\nLoad it in the GUI to convert it to the new version." << endl;
 	return false;
     }
diff --git a/src/nxosacl/nxosacl.cpp b/src/nxosacl/nxosacl.cpp
index 8946ee1ef..7d8c80587 100644
--- a/src/nxosacl/nxosacl.cpp
+++ b/src/nxosacl/nxosacl.cpp
@@ -75,7 +75,7 @@ class UpgradePredicate: public XMLTools::UpgradePredicate
     public:
     virtual bool operator()(const string &msg) const 
     { 
-        msg.size();  // to make compiler happy about unused parameter
+        (void)msg.size();  // to make compiler happy about unused parameter
 	cout << "Data file has been created in the old version of Firewall Builder.\nLoad it in the GUI to convert it to the new version." << endl;
 	return false;
     }
diff --git a/src/pix/pix.cpp b/src/pix/pix.cpp
index e27c63004..eea10dcbb 100644
--- a/src/pix/pix.cpp
+++ b/src/pix/pix.cpp
@@ -76,13 +76,13 @@ class UpgradePredicate: public XMLTools::UpgradePredicate
     public:
     virtual bool operator()(const string &msg) const 
     { 
-        msg.size();  // to make compiler happy about unused parameter
+        (void)msg.size();  // to make compiler happy about unused parameter
 	cout << "Data file has been created in the old version of Firewall Builder.\nLoad it in the GUI to convert it to the new version." << endl;
 	return false;
     }
 };
 
-    
+
 void usage(const char *name)
 {
     cout << "Firewall Builder:  policy compiler for Cisco PIX firewall (with support for FWSM)" << endl;
diff --git a/src/procurve_acl/procurve_acl.cpp b/src/procurve_acl/procurve_acl.cpp
index 9e3bfd7de..f85df98b8 100644
--- a/src/procurve_acl/procurve_acl.cpp
+++ b/src/procurve_acl/procurve_acl.cpp
@@ -75,7 +75,7 @@ class UpgradePredicate: public XMLTools::UpgradePredicate
     public:
     virtual bool operator()(const string &msg) const 
     { 
-        msg.size();  // to make compiler happy about unused parameter
+        (void)msg.size();  // to make compiler happy about unused parameter
 	cout << "Data file has been created in the old version of Firewall Builder.\nLoad it in the GUI to convert it to the new version." << endl;
 	return false;
     }