diff --git a/debug.opts b/debug.opts
index 282e35f5a6a20f6f8ceef414ea7cb2f3922be5f9..196c30d446cce51e8570101442d3cb77fc45c0bb 100644
--- a/debug.opts
+++ b/debug.opts
@@ -2,7 +2,7 @@
 DUMUXDIR=$(find $OLDPWD -name "dune.module" | xargs grep -El '[[:space:]]*Module:[[:space:]]*dumux[[:space:]]*$' | sed "s/dune.module//")
 
 # configure flags 
-CONFIGURE_FLAGS="CXXFLAGS=\"-I$DUMUXDIR -Wall -Wno-sign-compare -fno-strict-aliasing -g\" \
+CONFIGURE_FLAGS="CXXFLAGS=\"-I$DUMUXDIR -Wall -Wno-sign-compare -Wno-packed-bitfield-compat -fno-strict-aliasing -g\" \
   --enable-dunedevel \
   --enable-documentation \
   --disable-parallel \
diff --git a/dumux/common/boundarytypes.hh b/dumux/common/boundarytypes.hh
index 89a83811d5403d25791eca2cb7e97d2bff91ad59..4ca044a7f23804889291e1a9bc884cc44e4a295f 100644
--- a/dumux/common/boundarytypes.hh
+++ b/dumux/common/boundarytypes.hh
@@ -414,7 +414,7 @@ public:
 
 private:
     // this is a bitfield structure!
-    struct __packed__ {
+    struct __attribute__((__packed__)) {
         unsigned char visited : 1;
         unsigned char isDirichlet : 1;
         unsigned char isNeumann : 1;
diff --git a/optim.opts b/optim.opts
index bbed24f922ec1030bccf64f41397cd01a55d14cb..1baefc916ec4fe7b4551e1d068354e75c54b6143 100644
--- a/optim.opts
+++ b/optim.opts
@@ -2,7 +2,7 @@
 DUMUXDIR=$(find $OLDPWD -name "dune.module" | xargs grep -El '[[:space:]]*Module:[[:space:]]*dumux[[:space:]]*$' | sed "s/dune.module//")
 
 # configure flags 
-CONFIGURE_FLAGS="CXXFLAGS=\"-I$DUMUXDIR -Wall -Wno-sign-compare -fno-strict-aliasing -O3 -march=native -DNDEBUG\" \
+CONFIGURE_FLAGS="CXXFLAGS=\"-I$DUMUXDIR -Wall -Wno-sign-compare -Wno-packed-bitfield-compat -fno-strict-aliasing -O3 -march=native -DNDEBUG\" \
   --disable-dunedevel \
   --disable-documentation \
   --disable-parallel \