diff --git a/ippl/src/Meshes/Cartesian.hpp b/ippl/src/Meshes/Cartesian.hpp
index 589cf2e0da15480be3a263119063985651728b07..1541d1c4514bbfd8d5e05a7cec3d1dc07c0bc3b1 100644
--- a/ippl/src/Meshes/Cartesian.hpp
+++ b/ippl/src/Meshes/Cartesian.hpp
@@ -1563,7 +1563,7 @@ getVertRangeVolume(const NDIndex<Dim>& ndi) const
   }
   // Compute volume of rectangular solid beweeen these extremal vertices:
   MFLOAT volume = 1.0;
-  for (d=0; d<Dim; d++) volume *= abs(v1(d) - v0(d));
+  for (d=0; d<Dim; d++) volume *= std::abs(v1(d) - v0(d));
   return volume;
 }
 // Volume of range of cells spanned by input NDIndex (index of cells):
@@ -1593,7 +1593,7 @@ getCellRangeVolume(const NDIndex<Dim>& ndi) const
   }
   // Compute volume of rectangular solid beweeen these extremal vertices:
   MFLOAT volume = 1.0;
-  for (unsigned int d=0; d<Dim; d++) volume *= abs(v1(d) - v0(d));
+  for (unsigned int d=0; d<Dim; d++) volume *= std::abs(v1(d) - v0(d));
   return volume;
 }
 
diff --git a/tests/ippl_src/Field/Field.cpp b/tests/ippl_src/Field/Field.cpp
index be3afb7c60e1a3b4768fde5e10bc2e1f7a9dfe02..9dac003719a56d5c00555eec21b977a796cf2fe2 100644
--- a/tests/ippl_src/Field/Field.cpp
+++ b/tests/ippl_src/Field/Field.cpp
@@ -1202,9 +1202,9 @@ TEST(Field, SimpleTest8)
 
     Vektor<double,D3> p1(8,9,10);
 
-    Vektor<unsigned,D3> N(static_cast<unsigned> (ceil( (abs(boxMin[0])+boxMax[0])/h[0])),
-                           static_cast<unsigned> (ceil( (abs(boxMin[1])+boxMax[1])/h[1])),
-                           static_cast<unsigned> (ceil( (abs(boxMin[2])+boxMax[2])/h[2])));
+    Vektor<unsigned,D3> N(static_cast<unsigned> (std::ceil( (std::abs(boxMin[0])+boxMax[0])/h[0])),
+                          static_cast<unsigned> (std::ceil( (std::abs(boxMin[1])+boxMax[1])/h[1])),
+                          static_cast<unsigned> (std::ceil( (std::abs(boxMin[2])+boxMax[2])/h[2])));
 
     std::cout << "orig= " << boxMin << " maxext= " << boxMax << std::endl;
     std::cout << "h=  " << h << " N= " << N << std::endl;
diff --git a/tests/ippl_src/Meshes/Cartesian.cpp b/tests/ippl_src/Meshes/Cartesian.cpp
index 036438bd21d80f3ac4a164f1c0266a88e6c2949f..a428c00c553b2a355a855adced47f1232643751b 100644
--- a/tests/ippl_src/Meshes/Cartesian.cpp
+++ b/tests/ippl_src/Meshes/Cartesian.cpp
@@ -121,7 +121,7 @@ TEST(Meshes, Cartesian)
     assign(vectorVert, mesh.getVertexPositionField(vectorVert));
     scalarCell = Div(vectorVert, scalarCell);
     // The value should be 3.0 for all elements; test this:
-    EXPECT_NEAR(abs(sum(scalarCell)/totcells), 1.0*D, roundOffError);
+    EXPECT_NEAR(std::abs(sum(scalarCell)/totcells), 1.0*D, roundOffError);
     //---------------------------------------------------------------------------
 
     // --------------------------------------------------------------------------
@@ -160,7 +160,7 @@ TEST(Meshes, Cartesian)
     double magDiffVectorVert = 0.0;
     for (d = 0; d < D; d++) magDiffVectorVert += diffVectorVert(d)*diffVectorVert(d);
     magDiffVectorVert = sqrt(magDiffVectorVert);
-    EXPECT_NEAR(abs(magDiffVectorVert), 0, roundOffError);
+    EXPECT_NEAR(std::abs(magDiffVectorVert), 0, roundOffError);
     //---------------------------------------------------------------------------
 
     // --------------------------------------------------------------------------
@@ -198,7 +198,7 @@ TEST(Meshes, Cartesian)
     double magDiffVectorCell = 0.0;
     for (d = 0; d < D; d++) magDiffVectorCell += diffVectorCell(d)*diffVectorCell(d);
     magDiffVectorCell = sqrt(magDiffVectorCell);
-    EXPECT_NEAR(abs(magDiffVectorCell), 0, roundOffError);
+    EXPECT_NEAR(std::abs(magDiffVectorCell), 0, roundOffError);
     //---------------------------------------------------------------------------
 
     //---------------------------------------------------------------------------
@@ -224,7 +224,7 @@ TEST(Meshes, Cartesian)
     magDiffVectorVert = 0.0;
     for (d = 0; d < D; d++) magDiffVectorVert += diffVectorVert(d)*diffVectorVert(d);
     magDiffVectorVert = sqrt(magDiffVectorVert);
-    EXPECT_NEAR(abs(magDiffVectorCell), 0, roundOffError);
+    EXPECT_NEAR(std::abs(magDiffVectorCell), 0, roundOffError);
     //---------------------------------------------------------------------------
 
     // --------------------------------------------------------------------------
@@ -249,7 +249,7 @@ TEST(Meshes, Cartesian)
             magDiffTensorCell += diffTensorCell(d,d2)*diffTensorCell(d,d2);
         }
     }
-    EXPECT_NEAR(abs(magDiffTensorCell), 0, roundOffError);
+    EXPECT_NEAR(std::abs(magDiffTensorCell), 0, roundOffError);
     //---------------------------------------------------------------------------
 
     //---------------------------------------------------------------------------