diff --git a/core/libs/prx/libc/src/MathExact.cpp b/core/libs/prx/libc/src/MathExact.cpp
index bbfe5114eff4..fa9cc266432f 100644
--- a/core/libs/prx/libc/src/MathExact.cpp
+++ b/core/libs/prx/libc/src/MathExact.cpp
@@ -42,8 +42,8 @@ short TestExtended(const ExtendedBits& bits) {
     const int exponent = bits.signExponent & 0x7fff;
     const std::uint64_t fraction = bits.mantissa & 0x7fffffffffffffffull;
     if (exponent == 0x7fff) return fraction != 0 ? NotANumber : Infinite;
-    if (exponent != 0 || (bits.mantissa >> 63) != 0) return Finite;
-    return bits.mantissa != 0 ? Denormal : Zero;
+    if ((bits.mantissa >> 63) != 0) return Finite;
+    return exponent != 0 || bits.mantissa != 0 ? Denormal : Zero;
 }
 
 template<typename TFloat>
@@ -242,8 +242,9 @@ int APS5_VABI finitef_nid_postfix(float x) { return std::isfinite(x) ? 1 : 0; }
 
 int APS5_VABI __fpclassifyl_nid_postfix(long double x) {
     const ExtendedBits bits = Bits(x);
-    if ((bits.signExponent & 0x7fff) != 0 || bits.mantissa == 0) return TestExtended(bits);
-    return Denormal;
+    const int exponent = bits.signExponent & 0x7fff;
+    if (exponent == 0) return bits.mantissa != 0 ? Denormal : Zero;
+    return exponent != 0x7fff ? Finite : TestExtended(bits);
 }
 int APS5_VABI __isinfl_nid_postfix(long double x) { return TestExtended(Bits(x)) == Infinite ? 1 : 0; }
 int APS5_VABI __isnanl_nid_postfix(long double x) { return TestExtended(Bits(x)) == NotANumber ? 1 : 0; }
diff --git a/core/libs/tests/GuestMathExact.cpp b/core/libs/tests/GuestMathExact.cpp
index 5db64f610dd5..35d1e587dba9 100644
--- a/core/libs/tests/GuestMathExact.cpp
+++ b/core/libs/tests/GuestMathExact.cpp
@@ -130,6 +130,10 @@ static void CheckRoundingModes() {
 static void CheckClassification() {
     const long double pseudoDenormal = Extended(0x0000, 0x8000000000000000ull);
     Require(_LDtest_nid_postfix(&pseudoDenormal) == -1 && __fpclassifyl_nid_postfix(pseudoDenormal) == -2);
+    for (const long double unnormal : {Extended(0x3fff, 0x4000000000000000ull), Extended(0x8001, 0), Extended(0x7ffe, 0x7fffffffffffffffull)}) {
+        Require(_LDtest_nid_postfix(&unnormal) == -2 && _LDclass_nid_postfix(unnormal) == -2);
+        Require(__fpclassifyl_nid_postfix(unnormal) == -1 && __isnormall_nid_postfix(unnormal) == 1);
+    }
     const long double zero = 0.0L, infinity = INFINITY, nan = NAN, denormal = Extended(0, 1);
     Require(_LDtest_nid_postfix(&zero) == 0 && _LDtest_nid_postfix(&infinity) == 1 && _LDtest_nid_postfix(&nan) == 2 && _LDtest_nid_postfix(&denormal) == -2);
     Require(__fpclassifyl_nid_postfix(1.0L) == -1 && __fpclassifyl_nid_postfix(0.0L) == 0 && __fpclassifyl_nid_postfix(INFINITY) == 1);