diff --git a/src/compiler/nir/nir_lower_mediump.c b/src/compiler/nir/nir_lower_mediump.c
index c1baabf27ed..2e7a40d2359 100644
--- a/src/compiler/nir/nir_lower_mediump.c
+++ b/src/compiler/nir/nir_lower_mediump.c
@@ -749,7 +749,9 @@ static bool
 const_is_f16(nir_ssa_scalar scalar)
 {
    double value = nir_ssa_scalar_as_float(scalar);
-   return value == _mesa_half_to_float(_mesa_float_to_half(value));
+   uint16_t fp16_val = _mesa_float_to_half(value);
+   bool is_denorm = (fp16_val & 0x7fff) != 0 && (fp16_val & 0x7fff) <= 0x3ff;
+   return value == _mesa_half_to_float(fp16_val) && !is_denorm;
 }
 
 static bool