diff --git a/lib/BlockArray.cpp b/lib/BlockArray.cpp
index db9e6457..bb116299 100644
--- a/lib/BlockArray.cpp
+++ b/lib/BlockArray.cpp
@@ -230,7 +230,8 @@ bool BlockArray::setHistorySize(size_t newsize)
         return false;
     } else {
         decreaseBuffer(newsize);
-        ftruncate(ion, length*blocksize);
+        int res = ftruncate(ion, length*blocksize);
+        Q_UNUSED (res);
         size = newsize;
 
         return true;
diff --git a/lib/Vt102Emulation.cpp b/lib/Vt102Emulation.cpp
index f76092d9..93063505 100644
--- a/lib/Vt102Emulation.cpp
+++ b/lib/Vt102Emulation.cpp
@@ -940,7 +940,7 @@ void Vt102Emulation::sendMouseEvent( int cb, int cx, int cy , int eventType )
     if ((getMode(MODE_Mouse1002) || getMode(MODE_Mouse1003)) && eventType == 1)
       cb += 0x20; //add 32 to signify motion event
 
-    char command[32];
+    char command[40];
     command[0] = '\0';
     // Check the extensions in decreasing order of preference. Encoding the release event above assumes that 1006 comes first.
     if (getMode(MODE_Mouse1006)) {
diff --git a/lib/kpty.cpp b/lib/kpty.cpp
index 47f8dc8e..2cc22b29 100644
--- a/lib/kpty.cpp
+++ b/lib/kpty.cpp
@@ -467,7 +467,8 @@ void KPty::close()
         if (!geteuid()) {
             struct stat st;
             if (!stat(d->ttyName.data(), &st)) {
-                chown(d->ttyName.data(), 0, st.st_gid == getgid() ? 0 : -1);
+                int res = chown(d->ttyName.data(), 0, st.st_gid == getgid() ? 0 : -1);
+                Q_UNUSED (res);
                 chmod(d->ttyName.data(), S_IRUSR|S_IWUSR|S_IRGRP|S_IWGRP|S_IROTH|S_IWOTH);
             }
         } else {