diff --git a/common.pri b/common.pri
index 84f3e993dc..5d5e8870d9 100644
--- a/common.pri
+++ b/common.pri
@@ -102,7 +102,8 @@ win32-msvc2010 {
 }
 
 unix|win32-g++ {
-  QMAKE_CXXFLAGS_WARN_ON *= -Wno-sign-compare -Wno-strict-aliasing -Wconversion -Wno-unused-parameter
+  QMAKE_CXXFLAGS_WARN_ON *= -Wno-sign-compare -Wno-strict-aliasing -Wconversion -Wno-unused-parameter \
+                            -Wno-sign-conversion
   # experimental
   QMAKE_CFLAGS_RELEASE -= -O2
   QMAKE_CFLAGS_RELEASE += -O3