diff --git a/cij/data/constraints/trigonal6 b/cij/data/constraints/trigonal6
index 77df166..7b2a38c 100644
--- a/cij/data/constraints/trigonal6
+++ b/cij/data/constraints/trigonal6
@@ -1,7 +1,7 @@
 c11 = c22
 c13 = c23
 c14 = -c24 = c56
-c15 = -c25 = -c46
 c44 = c55
 c66 = (c11 - c12) / 2
 c16 = c26 = c34 = c35 = c36 = c45 = 0
+c15 = -c25 = -c46 = 0
diff --git a/cij/data/constraints/trigonal7 b/cij/data/constraints/trigonal7
index 9ecf054..77df166 100644
--- a/cij/data/constraints/trigonal7
+++ b/cij/data/constraints/trigonal7
@@ -1,7 +1,7 @@
 c11 = c22
 c13 = c23
-c14 = - c24 = c56 / 2
-c15 = - c25 = - c46 / 2
+c14 = -c24 = c56
+c15 = -c25 = -c46
 c44 = c55
 c66 = (c11 - c12) / 2
 c16 = c26 = c34 = c35 = c36 = c45 = 0