diff --git a/src/math/FGTable.cpp b/src/math/FGTable.cpp
index 62f2ab59b5..c14a1f5927 100644
--- a/src/math/FGTable.cpp
+++ b/src/math/FGTable.cpp
@@ -509,7 +509,8 @@ double FGTable::GetValue(double key) const
   double Span = Data[2*r] - x0;
   assert(Span > 0.0);
   double Factor = (key - x0) / Span;
-  assert(Factor >= 0.0 && Factor <= 1.0);
+  assert(Factor >= -EPSILON && Factor <= 1.0 + EPSILON);
+
 
   double y0 = Data[2*r-1];
   return Factor*(Data[2*r+1] - y0) + y0;
diff --git a/src/math/FGTable.h b/src/math/FGTable.h
index 1439c69cb7..20905e1eea 100644
--- a/src/math/FGTable.h
+++ b/src/math/FGTable.h
@@ -313,6 +313,8 @@ class JSBSIM_API FGTable : public FGParameter, public FGJSBBase
 
   std::string GetName(void) const {return Name;}
 
+  static constexpr double EPSILON = 1e-9;
+
 private:
   enum type {tt1D, tt2D, tt3D} Type;
   enum axis {eRow=0, eColumn, eTable};