diff --git a/src/REAX/pair_reax.cpp b/src/REAX/pair_reax.cpp
index a7f5c8ce2e..3f352846a1 100644
--- a/src/REAX/pair_reax.cpp
+++ b/src/REAX/pair_reax.cpp
@@ -335,7 +335,8 @@ void PairREAX::write_reax_vlist()
 	  iii = j+1;
 	  jjj = i+1;
 	}
-	if (nvpair >= nvpairmax) break;
+	if (nvpair >= nvpairmax) 
+	  error->one("reax_defs.h::NNEIGHMAXDEF too small");
 	
 	FORTRAN(cbkpairs, CBKPAIRS).nvl1[nvpair] = iii;
 	FORTRAN(cbkpairs, CBKPAIRS).nvl2[nvpair] = jjj;
@@ -393,7 +394,8 @@ void PairREAX::write_reax_vlist()
 	iii = i+1;
 	jjj = j+1;
 	      
-	if (nvpair >= nvpairmax) break;
+	if (nvpair >= nvpairmax) 
+	  error->one("reax_defs.h::NNEIGHMAXDEF too small");
 	
 	FORTRAN(cbkpairs, CBKPAIRS).nvl1[nvpair] = iii;
 	FORTRAN(cbkpairs, CBKPAIRS).nvl2[nvpair] = jjj;