diff --git a/tests/float/cmath_fun.py b/tests/float/cmath_fun.py
index ae5921c30..d3df25e11 100644
--- a/tests/float/cmath_fun.py
+++ b/tests/float/cmath_fun.py
@@ -50,6 +50,6 @@ for f_name, f, test_vals in functions:
         else:
             # some test (eg cmath.sqrt(-0.5)) disagree with CPython with tiny real part
             real = ret.real
-            if abs(real) < 1e15:
+            if abs(real) < 1e-6:
                 real = 0.
             print("complex(%.5g, %.5g)" % (real, ret.imag))