diff --git a/core/libs/prx/libc/src/Math.cpp b/core/libs/prx/libc/src/Math.cpp
index 90c19cb5f..f127140ab 100644
--- a/core/libs/prx/libc/src/Math.cpp
+++ b/core/libs/prx/libc/src/Math.cpp
@@ -182,7 +182,12 @@ float APS5_VABI asinf_nid_postfix(float x) {
     errno = saved_errno;
     return result;
 }
-float APS5_VABI acosf_nid_postfix(float x) { return std::acos(x); }
+float APS5_VABI acosf_nid_postfix(float x) {
+    const int saved_errno = errno;
+    const float result = std::acos(x);
+    errno = saved_errno;
+    return result;
+}
 float APS5_VABI atan2f_nid_postfix(float y, float x) { return std::atan2(y, x); }
 float APS5_VABI hypotf_nid_postfix(float x, float y) { return static_cast<float>(std::hypot(static_cast<double>(x), static_cast<double>(y))); }
 double APS5_VABI hypot_nid_postfix(double x, double y) {
diff --git a/core/libs/tests/GuestMath.cpp b/core/libs/tests/GuestMath.cpp
index 2f09ac820..cc1760c60 100644
--- a/core/libs/tests/GuestMath.cpp
+++ b/core/libs/tests/GuestMath.cpp
@@ -214,6 +214,16 @@ static void CheckPowfSpecialValue() {
     Require(std::bit_cast<std::uint32_t>(powf_nid_postfix(1.0f, std::bit_cast<float>(0x7f800001u))) == 0x3f800000u);
 }
 
+static void CheckAcosfErrno() {
+    errno = 0;
+    Require(std::bit_cast<std::uint32_t>(acosf_nid_postfix(2.0f)) == 0xffc00000u);
+    Require(errno == 0);
+    Require(std::bit_cast<std::uint32_t>(acosf_nid_postfix(-2.0f)) == 0xffc00000u);
+    Require(errno == 0);
+    Require(std::bit_cast<std::uint32_t>(acosf_nid_postfix(0.5f)) == 0x3f860a92u);
+    Require(errno == 0);
+}
+
 static void CheckLongDouble() {
     Require(ExtendedBits(acosl_nid_postfix(-1.0L), 0xc90fdaa22168c235ull, 0x4000));
     Require(ExtendedBits(acosl_nid_postfix(0.0L), 0xc90fdaa22168c235ull, 0x3fff));
@@ -839,6 +849,7 @@ int main() {
     Require(minimum.quot == -214748364 && minimum.rem == -8);
     CheckPowfSpecialValue();
     Require(abs_nid_postfix(0) == 0);
+    CheckAcosfErrno();
     Require(abs_nid_postfix(42) == 42);
     Require(abs_nid_postfix(-42) == 42);
     Require(abs_nid_postfix(std::numeric_limits<int>::max()) == std::numeric_limits<int>::max());