diff --git a/KEMField/Source/ExternalFields/MagfieldCoils/CMakeLists.txt b/KEMField/Source/ExternalFields/MagfieldCoils/CMakeLists.txt
index a492cd90e..22b8cee53 100644
--- a/KEMField/Source/ExternalFields/MagfieldCoils/CMakeLists.txt
+++ b/KEMField/Source/ExternalFields/MagfieldCoils/CMakeLists.txt
@@ -48,6 +48,7 @@ target_link_libraries (KEMMagfieldCoils
 #        KEMCore
 #        KEMMath
 #        KEMFieldSolverCore
+        KEMFieldExceptions
 )
 
 kasper_install_headers (${MAGFIELDCOILS_HEADERFILES})
diff --git a/KEMField/Source/ExternalFields/MagfieldCoils/src/MagfieldCoils.cxx b/KEMField/Source/ExternalFields/MagfieldCoils/src/MagfieldCoils.cxx
index 304c76aea..e9052b21c 100755
--- a/KEMField/Source/ExternalFields/MagfieldCoils/src/MagfieldCoils.cxx
+++ b/KEMField/Source/ExternalFields/MagfieldCoils/src/MagfieldCoils.cxx
@@ -1,4 +1,5 @@
 #include "MagfieldCoils.h"
+#include "KEMSimpleException.hh"
 
 
 MagfieldCoils::MagfieldCoils(string inputdirname, string inputobjectname, string inputcoilfilename, int inputNelliptic,
@@ -14,6 +15,9 @@ MagfieldCoils::MagfieldCoils(string inputdirname, string inputobjectname, string
     fcoilfilename = inputcoilfilename;  // name of coil input file
     fNelliptic =
         inputNelliptic;    // radial numerical integration parameter for magnetic field calc. with elliptic integrals
+    if(inputnmax <= 1) {
+        throw KEMField::KEMSimpleException("MagfieldCoils: nmax can't be <= 1. A recommended value for nmax is 500.\nThis error was added in May 2024, before results in this case could not be trusted.");
+    }
     fnmax = inputnmax;      // number of source coefficients for fixed source point: nmax+1
     fepstol = inputepstol;  // small tolerance parameter needed for the symmetry group definitions
                            // Recommended values: inputNelliptic=32, inputnmax=500, inputepstol=1.e-8.