diff --git a/regtest/basic/rt-hrex-0/out.reference b/regtest/basic/rt-hrex-0/out.reference
index 986db7d35620d38c8b0cd1323235c69c6dbf5396..70fe9f1321d6fa315da012f6b1d2c13ac75eef42 100644
--- a/regtest/basic/rt-hrex-0/out.reference
+++ b/regtest/basic/rt-hrex-0/out.reference
@@ -578,8 +578,8 @@ N   C   N            1   120.000    585.760  ; Added for Urea (same as N2-CA-N2)
 ; LINE(512) X   X   CM  HA       4      180.00     4.60240     2	 ; 
 ; LINE(513) X   X   CA  H4       4      180.00     4.60240     2	 ; bsd.on C6H6 nmodes 
 ; LINE(514) X   X   CA  H5       4      180.00     4.60240     2	 ; bsd.on C6H6 nmodes
-
-
+[ dihedraltypes ] 
+; LINE(516) X   X   X   X     9       0.0      1.60247     3   ; fake choice, just here to test gromacs 5.1.4 behavior
 [ dihedraltypes ] 
 ;i   j   k   l	   func	
 ; LINE(519)  CT  CT  OS  CT    9       0.0      1.60247     3   ; 
diff --git a/regtest/basic/rt-hrex-0/processed.top b/regtest/basic/rt-hrex-0/processed.top
index 88a87338e947e5c45d8b2eba574cbcb4cd48bfe4..5a6a213dd0ea66ff39f326f16bb1f4dbea0619cb 100644
--- a/regtest/basic/rt-hrex-0/processed.top
+++ b/regtest/basic/rt-hrex-0/processed.top
@@ -512,8 +512,8 @@ X   X   CM  H4       4      180.00     4.60240     2	;
 X   X   CM  HA       4      180.00     4.60240     2	; 
 X   X   CA  H4       4      180.00     4.60240     2	; bsd.on C6H6 nmodes 
 X   X   CA  H5       4      180.00     4.60240     2	; bsd.on C6H6 nmodes
-
-
+[ dihedraltypes ]
+X   X   X   X     9       0.0      1.60247     3  ; fake choice, just here to test gromacs 5.1.4 behavior
 [ dihedraltypes ]
 ;i   j   k   l	   func	
  CT  CT  OS  CT    9       0.0      1.60247     3  ;