diff --git a/tests/sdf/test_sdf_operations.cpp b/tests/sdf/test_sdf_operations.cpp
index e252495..083ef6b 100644
--- a/tests/sdf/test_sdf_operations.cpp
+++ b/tests/sdf/test_sdf_operations.cpp
@@ -75,8 +75,8 @@ TEST(SdfOperations, SmoothUnionBlending) {
     // With k > 0, result should be less than min(d1,d2) (blend digs in)
     double k = 0.1;
     double result = op_smooth_union(1.0, 1.0, k);
-    EXPECT_LT(result, 1.0);           // blend reduces distance
-    EXPECT_GT(result, 1.0 - k * 0.25); // bound: max reduction is k/4 at h=0.5
+    EXPECT_LT(result, 1.0);            // blend reduces distance
+    EXPECT_GE(result, 1.0 - k * 0.25); // bound: max reduction is k/4 at h=0.5
 
     // Far apart — should approach sharp union
     double far_result = op_smooth_union(1.0, 10.0, 0.1);
@@ -91,8 +91,8 @@ TEST(SdfOperations, SmoothIntersectionFallsBackToSharp) {
 TEST(SdfOperations, SmoothIntersectionBlending) {
     double k = 0.1;
     double result = op_smooth_intersection(1.0, 1.0, k);
-    EXPECT_GT(result, 1.0);          // blend increases distance
-    EXPECT_LT(result, 1.0 + k * 0.25);
+    EXPECT_GT(result, 1.0);            // blend increases distance
+    EXPECT_LE(result, 1.0 + k * 0.25); // bound: max increase is k/4 at h=0.5
 }
 
 TEST(SdfOperations, SmoothDifferenceFallsBackToSharp) {