diff --git a/epan/dissectors/packet-ngap.c b/epan/dissectors/packet-ngap.c
index a76403e8ac..724d6b538f 100644
--- a/epan/dissectors/packet-ngap.c
+++ b/epan/dissectors/packet-ngap.c
@@ -4616,7 +4616,7 @@ dissect_ngap_CellType(tvbuff_t *tvb _U_, int offset _U_, asn1_ctx_t *actx _U_, p
 static int
 dissect_ngap_ExpectedActivityPeriod(tvbuff_t *tvb _U_, int offset _U_, asn1_ctx_t *actx _U_, proto_tree *tree _U_, int hf_index _U_) {
   offset = dissect_per_constrained_integer(tvb, offset, actx, tree, hf_index,
-                                                            1U, 181U, NULL, FALSE);
+                                                            1U, 181U, NULL, TRUE);
 
   return offset;
 }
@@ -4626,7 +4626,7 @@ dissect_ngap_ExpectedActivityPeriod(tvbuff_t *tvb _U_, int offset _U_, asn1_ctx_
 static int
 dissect_ngap_ExpectedIdlePeriod(tvbuff_t *tvb _U_, int offset _U_, asn1_ctx_t *actx _U_, proto_tree *tree _U_, int hf_index _U_) {
   offset = dissect_per_constrained_integer(tvb, offset, actx, tree, hf_index,
-                                                            1U, 181U, NULL, FALSE);
+                                                            1U, 181U, NULL, TRUE);
 
   return offset;
 }
diff --git a/epan/dissectors/packet-s1ap.c b/epan/dissectors/packet-s1ap.c
index c9f8125a83..1f3d0df9e7 100644
--- a/epan/dissectors/packet-s1ap.c
+++ b/epan/dissectors/packet-s1ap.c
@@ -5914,7 +5914,7 @@ dissect_s1ap_EUTRANRoundTripDelayEstimationInfo(tvbuff_t *tvb _U_, int offset _U
 static int
 dissect_s1ap_ExpectedActivityPeriod(tvbuff_t *tvb _U_, int offset _U_, asn1_ctx_t *actx _U_, proto_tree *tree _U_, int hf_index _U_) {
   offset = dissect_per_constrained_integer(tvb, offset, actx, tree, hf_index,
-                                                            1U, 181U, NULL, FALSE);
+                                                            1U, 181U, NULL, TRUE);
 
   return offset;
 }
@@ -5924,7 +5924,7 @@ dissect_s1ap_ExpectedActivityPeriod(tvbuff_t *tvb _U_, int offset _U_, asn1_ctx_
 static int
 dissect_s1ap_ExpectedIdlePeriod(tvbuff_t *tvb _U_, int offset _U_, asn1_ctx_t *actx _U_, proto_tree *tree _U_, int hf_index _U_) {
   offset = dissect_per_constrained_integer(tvb, offset, actx, tree, hf_index,
-                                                            1U, 181U, NULL, FALSE);
+                                                            1U, 181U, NULL, TRUE);
 
   return offset;
 }
diff --git a/epan/dissectors/packet-x2ap.c b/epan/dissectors/packet-x2ap.c
index d271e9b982..378b4cd246 100644
--- a/epan/dissectors/packet-x2ap.c
+++ b/epan/dissectors/packet-x2ap.c
@@ -6104,7 +6104,7 @@ dissect_x2ap_EventType(tvbuff_t *tvb _U_, int offset _U_, asn1_ctx_t *actx _U_,
 static int
 dissect_x2ap_ExpectedActivityPeriod(tvbuff_t *tvb _U_, int offset _U_, asn1_ctx_t *actx _U_, proto_tree *tree _U_, int hf_index _U_) {
   offset = dissect_per_constrained_integer(tvb, offset, actx, tree, hf_index,
-                                                            1U, 181U, NULL, FALSE);
+                                                            1U, 181U, NULL, TRUE);
 
   return offset;
 }
@@ -6114,7 +6114,7 @@ dissect_x2ap_ExpectedActivityPeriod(tvbuff_t *tvb _U_, int offset _U_, asn1_ctx_
 static int
 dissect_x2ap_ExpectedIdlePeriod(tvbuff_t *tvb _U_, int offset _U_, asn1_ctx_t *actx _U_, proto_tree *tree _U_, int hf_index _U_) {
   offset = dissect_per_constrained_integer(tvb, offset, actx, tree, hf_index,
-                                                            1U, 181U, NULL, FALSE);
+                                                            1U, 181U, NULL, TRUE);
 
   return offset;
 }
diff --git a/epan/dissectors/packet-xnap.c b/epan/dissectors/packet-xnap.c
index 44e36689af..5ca7c8c2f2 100644
--- a/epan/dissectors/packet-xnap.c
+++ b/epan/dissectors/packet-xnap.c
@@ -4526,7 +4526,7 @@ dissect_xnap_EventType(tvbuff_t *tvb _U_, int offset _U_, asn1_ctx_t *actx _U_,
 static int
 dissect_xnap_ExpectedActivityPeriod(tvbuff_t *tvb _U_, int offset _U_, asn1_ctx_t *actx _U_, proto_tree *tree _U_, int hf_index _U_) {
   offset = dissect_per_constrained_integer(tvb, offset, actx, tree, hf_index,
-                                                            1U, 181U, NULL, FALSE);
+                                                            1U, 181U, NULL, TRUE);
 
   return offset;
 }
@@ -4557,7 +4557,7 @@ dissect_xnap_ExpectedHOInterval(tvbuff_t *tvb _U_, int offset _U_, asn1_ctx_t *a
 static int
 dissect_xnap_ExpectedIdlePeriod(tvbuff_t *tvb _U_, int offset _U_, asn1_ctx_t *actx _U_, proto_tree *tree _U_, int hf_index _U_) {
   offset = dissect_per_constrained_integer(tvb, offset, actx, tree, hf_index,
-                                                            1U, 181U, NULL, FALSE);
+                                                            1U, 181U, NULL, TRUE);
 
   return offset;
 }
diff --git a/tools/asn2wrs.py b/tools/asn2wrs.py
index 2be62b533c..dc6e0a953f 100755
--- a/tools/asn2wrs.py
+++ b/tools/asn2wrs.py
@@ -3548,7 +3548,7 @@ class Constraint (Node):
                 if self.subtype[0].IsValue() and self.subtype[1].IsValue():
                     v0 = self.subtype[0].GetValue(ectx)
                     v1 = self.subtype[1].GetValue(ectx)
-                    (minv, maxv, ext) = (ectx.value_min(v0[0],v1[0]), ectx.value_max(v0[1],v1[1]), v0[2] or v1[2])
+                    (minv, maxv, ext) = (ectx.value_min(v0[0],v1[0]), ectx.value_max(v0[1],v1[1]), hasattr(self, 'ext') and self.ext)
         return (minv, maxv, ext)
 
     def IsAlphabet(self):