diff --git a/Utilities/otbossimplugins/ossim/otb/Equation.cpp b/Utilities/otbossimplugins/ossim/otb/Equation.cpp
index 217bd757b106cb9652ec95858019a8bcaf645ef6..3c37fda5b152a602c84ff6da10a5a36325cd6619 100644
--- a/Utilities/otbossimplugins/ossim/otb/Equation.cpp
+++ b/Utilities/otbossimplugins/ossim/otb/Equation.cpp
@@ -124,7 +124,7 @@ void Equation::Normalisation()
   {
     /* Normalisation of the unknown for big values */
     _normalisationType = GreatValues;
-    _normalisationCoefficient = pow (10.0, (float)eMax) ;
+    _normalisationCoefficient = pow (10.0, (double)eMax) ;
     r    = 1.0 ;
     for (int i = _trueDegree-1 ; i >= 0 ; i--)
     {
@@ -136,7 +136,7 @@ void Equation::Normalisation()
   {
     /* Normalisation of the unknown for small */
     _normalisationType = SmallValues;
-    _normalisationCoefficient = pow(10.0,(float)(-eMin)) ;
+    _normalisationCoefficient = pow(10.0,(double)(-eMin)) ;
     r    = 1.0 ;
     for (int i = _trueDegree-1 ; i >= 0 ; i--)
     {