diff --git a/CHANGELOG.md b/CHANGELOG.md
index cbe1b3ab4..53613c3a4 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -78,6 +78,7 @@
     Bug #4545: Creatures flee from werewolves
     Bug #4551: Replace 0 sound range with default range separately
     Bug #4553: Forcegreeting on non-actor opens a dialogue window which cannot be closed
+    Bug #4558: Mesh optimizer: check for reserved node name is case-sensitive
     Feature #2606: Editor: Implemented (optional) case sensitive global search
     Feature #3083: Play animation when NPC is casting spell via script
     Feature #3103: Provide option for disposition to get increased by successful trade
diff --git a/apps/openmw_test_suite/misc/test_stringops.cpp b/apps/openmw_test_suite/misc/test_stringops.cpp
index 53a33dbf4..081ca8da6 100644
--- a/apps/openmw_test_suite/misc/test_stringops.cpp
+++ b/apps/openmw_test_suite/misc/test_stringops.cpp
@@ -7,7 +7,7 @@ struct PartialBinarySearchTest : public ::testing::Test
     std::vector<std::string> mDataVec;
     virtual void SetUp()
     {
-        const char* data[] = { "Head", "Chest", "Tri Head", "Tri Chest", "Bip01" };
+        const char* data[] = { "Head", "Chest", "Tri Head", "Tri Chest", "Bip01", "Tri Bip01" };
         mDataVec = std::vector<std::string>(data, data+sizeof(data)/sizeof(data[0]));
         std::sort(mDataVec.begin(), mDataVec.end(), Misc::StringUtils::ciLess);
     }
@@ -29,7 +29,15 @@ TEST_F(PartialBinarySearchTest, partial_binary_search_test)
     EXPECT_TRUE( matches("Tri Head 01") );
     EXPECT_TRUE( matches("Tri Head") );
     EXPECT_TRUE( matches("tri head") );
+    EXPECT_TRUE( matches("Tri bip01") );
+    EXPECT_TRUE( matches("bip01") );
+    EXPECT_TRUE( matches("bip01 head") );
+    EXPECT_TRUE( matches("Bip01 L Hand") );
+    EXPECT_TRUE( matches("BIp01 r Clavicle") );
+    EXPECT_TRUE( matches("Bip01 SpiNe1") );
 
+    EXPECT_FALSE( matches("") );
+    EXPECT_FALSE( matches("Node Bip01") );
     EXPECT_FALSE( matches("Hea") );
     EXPECT_FALSE( matches(" Head") );
     EXPECT_FALSE( matches("Tri  Head") );
diff --git a/components/misc/stringops.hpp b/components/misc/stringops.hpp
index 0fde1c96c..79fa36d1e 100644
--- a/components/misc/stringops.hpp
+++ b/components/misc/stringops.hpp
@@ -146,8 +146,15 @@ public:
         std::string::const_iterator yit = y.begin();
         for(;xit != x.end() && yit != y.end() && len > 0;++xit,++yit,--len)
         {
-            int res = *xit - *yit;
-            if(res != 0 && toLower(*xit) != toLower(*yit))
+            char left = *xit;
+            char right = *yit;
+            if (left == right)
+                continue;
+
+            left = toLower(left);
+            right = toLower(right);
+            int res = left - right;
+            if(res != 0)
                 return (res > 0) ? 1 : -1;
         }
         if(len > 0)
diff --git a/components/resource/scenemanager.cpp b/components/resource/scenemanager.cpp
index 03b850fac..db8d99ab4 100644
--- a/components/resource/scenemanager.cpp
+++ b/components/resource/scenemanager.cpp
@@ -393,9 +393,9 @@ namespace Resource
             static std::vector<std::string> reservedNames;
             if (reservedNames.empty())
             {
-                const char* reserved[] = {"Head", "Neck", "Chest", "Groin", "Right Hand", "Left Hand", "Right Wrist", "Left Wrist", "Shield Bone", "Right Forearm", "Left Forearm", "Right Upper Arm", "Left Upper Arm", "Right Foot", "Left Foot", "Right Ankle", "Left Ankle", "Right Knee", "Left Knee", "Right Upper Leg", "Left Upper Leg", "Right Clavicle", "Left Clavicle", "Weapon Bone", "Tail",
-                                         "Bip01 L Hand", "Bip01 R Hand", "Bip01 Head", "Bip01 Spine1", "Bip01 Spine2", "Bip01 L Clavicle", "Bip01 R Clavicle", "bip01", "Root Bone", "Bip01 Neck",
-                                         "BoneOffset", "AttachLight", "ArrowBone", "Camera"};
+                const char* reserved[] = {"Head", "Neck", "Chest", "Groin", "Right Hand", "Left Hand", "Right Wrist", "Left Wrist", "Shield Bone", "Right Forearm", "Left Forearm", "Right Upper Arm",
+                                          "Left Upper Arm", "Right Foot", "Left Foot", "Right Ankle", "Left Ankle", "Right Knee", "Left Knee", "Right Upper Leg", "Left Upper Leg", "Right Clavicle",
+                                          "Left Clavicle", "Weapon Bone", "Tail", "Bip01", "Root Bone", "BoneOffset", "AttachLight", "ArrowBone", "Camera"};
                 reservedNames = std::vector<std::string>(reserved, reserved + sizeof(reserved)/sizeof(reserved[0]));
 
                 for (unsigned int i=0; i<sizeof(reserved)/sizeof(reserved[0]); ++i)