diff --git a/test/testautomation_math.c b/test/testautomation_math.c
index 9ae968ed7..6aa9ba065 100644
--- a/test/testautomation_math.c
+++ b/test/testautomation_math.c
@@ -2137,15 +2137,17 @@ static int
 acos_precisionTest(void *args)
 {
     const d_to_d precision_cases[] = {
-        { 0.1, 14706289056.0 },
-        { 0.2, 13694384060.0 },
-        { 0.3, 12661036727.0 },
-        { 0.4, 11592794807.0 },
-        { 0.5, 10471975511.0 },
-        { 0.6, 9272952180.0 },
-        { 0.7, 7953988301.0 },
-        { 0.8, 6435011087.0 },
         { 0.9, 4510268117.0 },
+        { 0.8, 6435011087.0 },
+        { 0.7, 7953988301.0 },
+        { 0.6, 9272952180.0 },
+        { 0.5, 10471975511.0 },
+        { 0.4, 11592794807.0 },
+        { 0.3, 12661036727.0 },
+        { 0.2, 13694384060.0 },
+        { 0.1, 14706289056.0 },
+        { 0.0, 15707963267.0 },
+        { -0.0, 15707963267.0 },
         { -0.1, 16709637479.0 },
         { -0.2, 17721542475.0 },
         { -0.3, 18754889808.0 },