diff --git a/src/modules/moduleSolver.f90 b/src/modules/moduleSolver.f90
index 6e23c6f..4142549 100644
--- a/src/modules/moduleSolver.f90
+++ b/src/modules/moduleSolver.f90
@@ -27,7 +27,7 @@ MODULE moduleSolver
 
   INTERFACE
     !Push a particle
-    SUBROUTINE push_interafece(part, tauIn)
+    PURE SUBROUTINE push_interafece(part, tauIn)
       USE moduleSpecies
 
       TYPE(particle), INTENT(inout):: part
@@ -214,7 +214,7 @@ MODULE moduleSolver
 
     END SUBROUTINE pushCartElectrostatic
 
-    SUBROUTINE pushCartElectromagnetic(part, tauIn)
+    PURE SUBROUTINE pushCartElectromagnetic(part, tauIn)
       USE moduleSPecies
       USE moduleEM
       USE moduleMath