diff --git a/src/mol-model/structure/model/properties/utils/secondary-structure.ts b/src/mol-model/structure/model/properties/utils/secondary-structure.ts
index 2d01032f84d00aed1d95c70edac7eb58e4c7ed2c..2ebb150cf6386d583f2f9777f3abddfbe6651c52 100644
--- a/src/mol-model/structure/model/properties/utils/secondary-structure.ts
+++ b/src/mol-model/structure/model/properties/utils/secondary-structure.ts
@@ -86,7 +86,7 @@ namespace DSSPType {
 }
 
 /** max distance between two C-alpha atoms to check for hbond */
-const caMaxDist = 9.0;
+const caMaxDist = 7.0;
 
 function calcAtomicTraceLookup3D(hierarchy: AtomicHierarchy, conformation: AtomicConformation) {
     const { x, y, z } = conformation;