diff --git a/core/libs/prx/libc/src/Strings.cpp b/core/libs/prx/libc/src/Strings.cpp
index 564458ace..4b8732386 100644
--- a/core/libs/prx/libc/src/Strings.cpp
+++ b/core/libs/prx/libc/src/Strings.cpp
@@ -221,24 +221,21 @@ char16_t* APS5_VABI wmemmove_nid_postfix(char16_t* dest, const char16_t* src, si
 extern "C" {
 
 int APS5_VABI strcasecmp_nid_postfix(const char* s1, const char* s2) {
-    while (*s1 && *s2) {
-        unsigned char a = static_cast<unsigned char>(std::tolower(static_cast<unsigned char>(*s1)));
-        unsigned char b = static_cast<unsigned char>(std::tolower(static_cast<unsigned char>(*s2)));
-        if (a != b) return a - b;
-        ++s1; ++s2;
+    for (;; ++s1, ++s2) {
+        const int a = std::tolower(static_cast<unsigned char>(*s1));
+        const int b = std::tolower(static_cast<unsigned char>(*s2));
+        if (a != b || *s1 == 0) return a - b;
     }
-    return static_cast<unsigned char>(*s1) - static_cast<unsigned char>(*s2);
 }
 
 int APS5_VABI strncasecmp_nid_postfix(const char* s1, const char* s2, size_t n) {
-    while (n && *s1 && *s2) {
-        unsigned char a = static_cast<unsigned char>(std::tolower(static_cast<unsigned char>(*s1)));
-        unsigned char b = static_cast<unsigned char>(std::tolower(static_cast<unsigned char>(*s2)));
+    for (; n != 0; ++s1, ++s2, --n) {
+        const int a = std::tolower(static_cast<unsigned char>(*s1));
+        const int b = std::tolower(static_cast<unsigned char>(*s2));
         if (a != b) return a - b;
-        ++s1; ++s2; --n;
+        if (*s1 == 0) break;
     }
-    if (!n) return 0;
-    return static_cast<unsigned char>(*s1) - static_cast<unsigned char>(*s2);
+    return 0;
 }
 
 int APS5_VABI bcmp_nid_postfix(const void* s1, const void* s2, size_t n) {
diff --git a/core/libs/tests/GuestStrings.cpp b/core/libs/tests/GuestStrings.cpp
index 4ae9225c7..ec0b4f01d 100644
--- a/core/libs/tests/GuestStrings.cpp
+++ b/core/libs/tests/GuestStrings.cpp
@@ -11,6 +11,8 @@ char* APS5_VABI basename_nid_postfix(const char*);
 char* APS5_VABI __inet_ntoa_nid_postfix(unsigned int);
 char* APS5_VABI dirname_nid_postfix(const char*);
 int* APS5_VABI __error_nid_postfix();
+int APS5_VABI strcasecmp_nid_postfix(const char*, const char*);
+int APS5_VABI strncasecmp_nid_postfix(const char*, const char*, std::size_t);
 std::size_t APS5_VABI strnlen_nid_postfix(const char*, std::size_t);
 std::size_t APS5_VABI strnlen_s_nid_postfix(const char*, std::size_t);
 char* APS5_VABI strncat_nid_postfix(char*, const char*, std::size_t);
@@ -98,6 +100,18 @@ static void CheckBoundsCheckedFunctions() {
     Require(snprintf_s_nid_postfix(formatted, sizeof(formatted), "%d-%s", 42, "x") == 4 && std::strcmp(formatted, "42-x") == 0);
 }
 
+static void CheckCaseInsensitiveComparison() {
+    Require(strcasecmp_nid_postfix("", "") == 0 && strcasecmp_nid_postfix("AbC", "aBc") == 0);
+    Require(strcasecmp_nid_postfix("A", "b") == 'a' - 'b' && strcasecmp_nid_postfix("b", "A") == 'b' - 'a');
+    Require(strcasecmp_nid_postfix("ab", "A") == 'b' && strcasecmp_nid_postfix("AB", "a") == 'b');
+    Require(strcasecmp_nid_postfix("A", "aB") == -'b' && strcasecmp_nid_postfix("a", "AB") == -'b');
+    Require(strcasecmp_nid_postfix("", "Z") == -'z' && strcasecmp_nid_postfix("Z", "") == 'z');
+    Require(strncasecmp_nid_postfix("abc", "ABD", 2) == 0 && strncasecmp_nid_postfix("abc", "ABD", 3) == 'c' - 'd');
+    Require(strncasecmp_nid_postfix("Ab", "a", 2) == 'b' && strncasecmp_nid_postfix("a", "AB", 5) == -'b');
+    Require(strncasecmp_nid_postfix("Q", "", 1) == 'q' && strncasecmp_nid_postfix("", "Q", 1) == -'q');
+    Require(strncasecmp_nid_postfix("x", "y", 0) == 0 && strncasecmp_nid_postfix("same", "SAME", 99) == 0);
+}
+
 static void CheckSscanfS() {
 #ifndef _WIN32
     int number = 0;
@@ -166,6 +180,7 @@ static bool CheckDirnameLengths() {
 int main() {
     if (!CheckDirnameLengths()) return 1;
     CheckBoundsCheckedFunctions();
+    CheckCaseInsensitiveComparison();
     CheckSscanfS();
     Require(std::strcmp(dirname_nid_postfix(nullptr), ".") == 0);
     char emptyPath[] = "";