diff --git a/dune/fufem/functionspacebases/conformingbasis.hh b/dune/fufem/functionspacebases/conformingbasis.hh
index 218b9f4d3c5a2e140df0d1d3445a4803c003db70..7a48e368317b02e4bfa640846fb38717424899df 100644
--- a/dune/fufem/functionspacebases/conformingbasis.hh
+++ b/dune/fufem/functionspacebases/conformingbasis.hh
@@ -99,7 +99,7 @@ class ConformingBasis :
                 dofConstraints_->setupFromBasis<NonconformingBasis>(ncBasis_);
         }
 
-        int size() const
+        size_t size() const
         {
             return ncBasis_.size();
         }
diff --git a/dune/fufem/functionspacebases/dgpqkbasis.hh b/dune/fufem/functionspacebases/dgpqkbasis.hh
index da4dd5b4b89867fd51e4350fcb66cc30108b7b94..c34022e54941b413c2291ce513905e2ccff8e008 100644
--- a/dune/fufem/functionspacebases/dgpqkbasis.hh
+++ b/dune/fufem/functionspacebases/dgpqkbasis.hh
@@ -44,7 +44,7 @@ class DgPQKBasis :
             dgIndexSet_(gridview)
         	{}
 
-        int size() const
+        size_t size() const
         {
             return dgIndexSet_.size();
         }
diff --git a/dune/fufem/functionspacebases/extensionbasis.hh b/dune/fufem/functionspacebases/extensionbasis.hh
index 034b3398a17801971cabb4484acee423141aab81..f8af04b231157ddb7189c2974b840b2802e517a5 100644
--- a/dune/fufem/functionspacebases/extensionbasis.hh
+++ b/dune/fufem/functionspacebases/extensionbasis.hh
@@ -57,7 +57,7 @@ class ExtensionBasis :
             update();
         }
 
-        int size() const
+        size_t size() const
         {
             return extendedBasis_.size();
         }
diff --git a/dune/fufem/functionspacebases/functionspacebasis.hh b/dune/fufem/functionspacebases/functionspacebasis.hh
index a2fc4753907a8cda5a51ddd7bc644ee6301f239f..252acb4444c49936cf870be538ea782fbd64761d 100644
--- a/dune/fufem/functionspacebases/functionspacebasis.hh
+++ b/dune/fufem/functionspacebases/functionspacebasis.hh
@@ -33,7 +33,7 @@ class FunctionSpaceBasis
             gridview_(gridview)
         {}
 
-        virtual int size() const
+        virtual size_t size() const
         {
             DUNE_THROW(Dune::NotImplemented, "You called the empty base class method");
         }
diff --git a/dune/fufem/functionspacebases/p0basis.hh b/dune/fufem/functionspacebases/p0basis.hh
index 67ae110fa9278d39e7ad92169b0d39180b3101ab..3a6d132129e8db0c71eaa1e5f9a63e22e4c68aae 100644
--- a/dune/fufem/functionspacebases/p0basis.hh
+++ b/dune/fufem/functionspacebases/p0basis.hh
@@ -50,7 +50,7 @@ class P0Basis :
             mapper_(gridview)
         {}
 
-        int size() const
+        size_t size() const
         {
             return mapper_.size();
         }
diff --git a/dune/fufem/functionspacebases/p1nodalbasis.hh b/dune/fufem/functionspacebases/p1nodalbasis.hh
index f4bf8a506d372341d9283516ee3a370d814567ba..d14a53c092a2ef3295d8e6a974f29da3b0e6f0fc 100644
--- a/dune/fufem/functionspacebases/p1nodalbasis.hh
+++ b/dune/fufem/functionspacebases/p1nodalbasis.hh
@@ -44,7 +44,7 @@ class P1NodalBasis :
             Base(gridview)
         {}
 
-        int size() const
+        size_t size() const
         {
             return gridview_.indexSet().size(dim);
         }
diff --git a/dune/fufem/functionspacebases/p2hierarchicalbasis.hh b/dune/fufem/functionspacebases/p2hierarchicalbasis.hh
index 8023123b20cd6dfedd8ac6977e274b1e4a3c5a80..c476a6dc9ef6a998a69e02fbfb89ab9c86e1547e 100644
--- a/dune/fufem/functionspacebases/p2hierarchicalbasis.hh
+++ b/dune/fufem/functionspacebases/p2hierarchicalbasis.hh
@@ -46,7 +46,7 @@ class P2HierarchicalBasis :
             mapper_(gridview)
         {}
 
-        int size() const
+        size_t size() const
         {
             return mapper_.size();
         }
diff --git a/dune/fufem/functionspacebases/p2hierarchicalwithelementbubblesbasis.hh b/dune/fufem/functionspacebases/p2hierarchicalwithelementbubblesbasis.hh
index c033120814960b890e74da1c9a4f83c62b2abf4f..4f0f7947b026c2f6180e4225147297196dedeeb0 100644
--- a/dune/fufem/functionspacebases/p2hierarchicalwithelementbubblesbasis.hh
+++ b/dune/fufem/functionspacebases/p2hierarchicalwithelementbubblesbasis.hh
@@ -54,7 +54,7 @@ class P2HierarchicalWithElementBubblesBasis :
             localFE_()
         {}
 
-        int size() const
+        size_t size() const
         {
             return mapper_.size();
         }
diff --git a/dune/fufem/functionspacebases/p2nodalbasis.hh b/dune/fufem/functionspacebases/p2nodalbasis.hh
index 71dc7f8efc6740dc42a916a41e7d124b5dd50ebb..f94527b20f360257b8779a972e4dcffabe7ecf4a 100644
--- a/dune/fufem/functionspacebases/p2nodalbasis.hh
+++ b/dune/fufem/functionspacebases/p2nodalbasis.hh
@@ -81,7 +81,7 @@ class P2NodalBasis :
             mapper_(gridview)
         {}
 
-        int size() const
+        size_t size() const
         {
             return mapper_.size();
         }
diff --git a/dune/fufem/functionspacebases/p3nodalbasis.hh b/dune/fufem/functionspacebases/p3nodalbasis.hh
index 519f61748be704c20c5adf2ab6336cbf81d2a7a3..db8809f80ffaec3c588ac3847efdd4512ba6f523 100644
--- a/dune/fufem/functionspacebases/p3nodalbasis.hh
+++ b/dune/fufem/functionspacebases/p3nodalbasis.hh
@@ -66,7 +66,7 @@ class P3NodalBasis :
         }
 
         /** \brief The number of degrees of freedom of the function space */
-        int size() const
+        size_t size() const
         {
             switch (dim) {
                 case 1:
diff --git a/dune/fufem/functionspacebases/q1nodalbasis.hh b/dune/fufem/functionspacebases/q1nodalbasis.hh
index 38918eadb98247d0899a7a888e089147423d6388..bd28259dfa04e6e71142a0243637e0f9ec1defe7 100644
--- a/dune/fufem/functionspacebases/q1nodalbasis.hh
+++ b/dune/fufem/functionspacebases/q1nodalbasis.hh
@@ -42,7 +42,7 @@ class Q1NodalBasis :
             localFE_()
         {}
 
-        int size() const
+        size_t size() const
         {
             return gridview_.indexSet().size(dim);
         }
diff --git a/dune/fufem/functionspacebases/reducedconformingbasis.hh b/dune/fufem/functionspacebases/reducedconformingbasis.hh
index 599b49953a67a6e6ca7edc93ef446d1502b7689e..0d3829ced8bda8d9e906d0e67229337ef803f513 100644
--- a/dune/fufem/functionspacebases/reducedconformingbasis.hh
+++ b/dune/fufem/functionspacebases/reducedconformingbasis.hh
@@ -74,7 +74,7 @@ class ReducedConformingBasis :
             reorder();
         }
 
-        int size() const
+        size_t size() const
         {
             return unconstrainedSize_;
         }
diff --git a/dune/fufem/functionspacebases/refinedp0basis.hh b/dune/fufem/functionspacebases/refinedp0basis.hh
index 102a99864a4af5708fec7e24b603d5bc5fa6c8f6..5336da62ff02fbd519d59c6b7764a3163de247be 100644
--- a/dune/fufem/functionspacebases/refinedp0basis.hh
+++ b/dune/fufem/functionspacebases/refinedp0basis.hh
@@ -52,7 +52,7 @@ class RefinedP0Basis :
             mapper_.update();
         }
 
-        int size() const
+        size_t size() const
         {
             return mapper_.size() * localFE_.localBasis().size();
         }
diff --git a/dune/fufem/functionspacebases/refinedp1nodalbasis.hh b/dune/fufem/functionspacebases/refinedp1nodalbasis.hh
index 1490fc4dc70046479f744828e1189297857ddd7e..7c3080619ff0808d90681e862e8a0c718f8b3a9d 100644
--- a/dune/fufem/functionspacebases/refinedp1nodalbasis.hh
+++ b/dune/fufem/functionspacebases/refinedp1nodalbasis.hh
@@ -44,7 +44,7 @@ class RefinedP1NodalBasis :
             mapper_(gridview)
         {}
 
-        int size() const
+        size_t size() const
         {
             return mapper_.size();
         }