diff --git a/Lib/test/test_complex.py b/Lib/test/test_complex.py
index bd3890e3398..5f623a10fb3 100644
--- a/Lib/test/test_complex.py
+++ b/Lib/test/test_complex.py
@@ -11,6 +11,8 @@ warnings.filterwarnings(
 from random import random
 from math import atan2
 
+INF = float("inf")
+NAN = float("nan")
 # These tests ensure that complex math does the right thing
 
 class ComplexTest(unittest.TestCase):
@@ -337,6 +339,18 @@ class ComplexTest(unittest.TestCase):
         self.assertEqual(-6j,complex(repr(-6j)))
         self.assertEqual(6j,complex(repr(6j)))
 
+        self.assertEqual(repr(complex(1., INF)), "(1+inf*j)")
+        self.assertEqual(repr(complex(1., -INF)), "(1-inf*j)")
+        self.assertEqual(repr(complex(INF, 1)), "(inf+1j)")
+        self.assertEqual(repr(complex(-INF, INF)), "(-inf+inf*j)")
+        self.assertEqual(repr(complex(NAN, 1)), "(nan+1j)")
+        self.assertEqual(repr(complex(1, NAN)), "(1+nan*j)")
+        self.assertEqual(repr(complex(NAN, NAN)), "(nan+nan*j)")
+
+        self.assertEqual(repr(complex(0, INF)), "inf*j")
+        self.assertEqual(repr(complex(0, -INF)), "-inf*j")
+        self.assertEqual(repr(complex(0, NAN)), "nan*j")
+
     def test_neg(self):
         self.assertEqual(-(1+6j), -1-6j)
 
diff --git a/Misc/NEWS b/Misc/NEWS
index 134ac7e7167..c4d64ceda64 100644
--- a/Misc/NEWS
+++ b/Misc/NEWS
@@ -12,6 +12,9 @@ What's New in Python 2.6 alpha 1?
 Core and builtins
 -----------------
 
+- Fixed repr() and str() of complex numbers with infinity or nan as real or
+  imaginary part.
+
 - Clear all free list during a gc.collect() of the highest generation in order
   to allow pymalloc to free more arenas. Python may give back memory to the
   OS earlier.
diff --git a/Objects/complexobject.c b/Objects/complexobject.c
index 4777ed14819..c87b9e8de2a 100644
--- a/Objects/complexobject.c
+++ b/Objects/complexobject.c
@@ -322,16 +322,49 @@ complex_to_buf(char *buf, int bufsz, PyComplexObject *v, int precision)
 {
 	char format[32];
 	if (v->cval.real == 0.) {
-		PyOS_snprintf(format, sizeof(format), "%%.%ig", precision);
-		PyOS_ascii_formatd(buf, bufsz - 1, format, v->cval.imag);
-		strncat(buf, "j", 1);
+		if (!Py_IS_FINITE(v->cval.imag)) {
+			if (Py_IS_NAN(v->cval.imag))
+				strncpy(buf, "nan*j", 6);
+			/* else if (copysign(1, v->cval.imag) == 1) */
+			else if (v->cval.imag > 0)
+				strncpy(buf, "inf*j", 6);
+			else
+				strncpy(buf, "-inf*j", 7);
+		}
+		else {
+			PyOS_snprintf(format, sizeof(format), "%%.%ig", precision);
+			PyOS_ascii_formatd(buf, bufsz - 1, format, v->cval.imag);
+			strncat(buf, "j", 1);
+		}
 	} else {
 		char re[64], im[64];
 		/* Format imaginary part with sign, real part without */
-		PyOS_snprintf(format, sizeof(format), "%%.%ig", precision);
-		PyOS_ascii_formatd(re, sizeof(re), format, v->cval.real);
-		PyOS_snprintf(format, sizeof(format), "%%+.%ig", precision);
-		PyOS_ascii_formatd(im, sizeof(im), format, v->cval.imag);
+		if (!Py_IS_FINITE(v->cval.real)) {
+			if (Py_IS_NAN(v->cval.real))
+				strncpy(re, "nan", 4);
+			/* else if (copysign(1, v->cval.real) == 1) */
+			else if (v->cval.real > 0)
+				strncpy(re, "inf", 4);
+			else
+				strncpy(re, "-inf", 5);
+		}
+		else {
+			PyOS_snprintf(format, sizeof(format), "%%.%ig", precision);
+			PyOS_ascii_formatd(re, sizeof(re), format, v->cval.real);
+		}
+		if (!Py_IS_FINITE(v->cval.imag)) {
+			if (Py_IS_NAN(v->cval.imag))
+				strncpy(im, "+nan*", 6);
+			/* else if (copysign(1, v->cval.imag) == 1) */
+			else if (v->cval.imag > 0)
+				strncpy(im, "+inf*", 6);
+			else
+				strncpy(im, "-inf*", 6);
+		}
+		else {
+			PyOS_snprintf(format, sizeof(format), "%%+.%ig", precision);
+			PyOS_ascii_formatd(im, sizeof(im), format, v->cval.imag);
+		}
 		PyOS_snprintf(buf, bufsz, "(%s%sj)", re, im);
 	}
 }