diff --git a/Objects/complexobject.c b/Objects/complexobject.c
index 691809f..4dd6151 100644
--- a/Objects/complexobject.c
+++ b/Objects/complexobject.c
@@ -799,25 +799,26 @@
 	*/
 
 	/* first look for forms starting with <float> */
-	errno = 0;
-	z = PyOS_ascii_strtod(s, &end);
-	if (end == s && errno == ENOMEM)
-		return PyErr_NoMemory();
-	if (errno == ERANGE && fabs(z) >= 1.0)
-		goto overflow;
-
+	z = PyOS_string_to_double(s, &end, PyExc_OverflowError);
+	if (z == -1.0 && PyErr_Occurred()) {
+		if (PyErr_ExceptionMatches(PyExc_ValueError))
+			PyErr_Clear();
+		else
+			return NULL;
+	}
 	if (end != s) {
 		/* all 4 forms starting with <float> land here */
 		s = end;
 		if (*s == '+' || *s == '-') {
 			/* <float><signed-float>j | <float><sign>j */
 			x = z;
-			errno = 0;
-			y = PyOS_ascii_strtod(s, &end);
-			if (end == s && errno == ENOMEM)
-				return PyErr_NoMemory();
-			if (errno == ERANGE && fabs(y) >= 1.0)
-				goto overflow;
+			y = PyOS_string_to_double(s, &end, PyExc_OverflowError);
+			if (y == -1.0 && PyErr_Occurred()) {
+				if (PyErr_ExceptionMatches(PyExc_ValueError))
+					PyErr_Clear();
+				else
+					return NULL;
+			}
 			if (end != s)
 				/* <float><signed-float>j */
 				s = end;
@@ -877,11 +878,6 @@
 	PyErr_SetString(PyExc_ValueError,
 			"complex() arg is a malformed string");
 	return NULL;
-
-  overflow:
-	PyErr_SetString(PyExc_OverflowError,
-			"complex() arg overflow");
-	return NULL;
 }
 
 static PyObject *
diff --git a/Objects/floatobject.c b/Objects/floatobject.c
index fdca3be..0619877 100644
--- a/Objects/floatobject.c
+++ b/Objects/floatobject.c
@@ -193,36 +193,20 @@
 	/* We don't care about overflow or underflow.  If the platform
 	 * supports them, infinities and signed zeroes (on underflow) are
 	 * fine. */
-	errno = 0;
-	PyFPE_START_PROTECT("strtod", goto error)
-	x = PyOS_ascii_strtod(s, (char **)&end);
-	PyFPE_END_PROTECT(x)
-	if (end == s) {
-		if (errno == ENOMEM)
-			PyErr_NoMemory();
-		else {
-			PyOS_snprintf(buffer, sizeof(buffer),
-				"invalid literal for float(): %.200s", s);
-			PyErr_SetString(PyExc_ValueError, buffer);
-		}
+	x = PyOS_string_to_double(s, (char **)&end, NULL);
+	if (x == -1.0 && PyErr_Occurred())
 		goto error;
-	}
-	/* Since end != s, the platform made *some* kind of sense out
-	   of the input.  Trust it. */
 	while (*end && isspace(Py_CHARMASK(*end)))
 		end++;
-	if (end != last) {
-		if (*end == '\0')
-			PyErr_SetString(PyExc_ValueError,
-					"null byte in argument for float()");
-		else {
-			PyOS_snprintf(buffer, sizeof(buffer),
-				"invalid literal for float(): %.200s", s);
-			PyErr_SetString(PyExc_ValueError, buffer);
-		}
-		goto error;
+	if (end == last)
+		result = PyFloat_FromDouble(x);
+	else {
+		PyOS_snprintf(buffer, sizeof(buffer),
+			      "invalid literal for float(): %.200s", s);
+		PyErr_SetString(PyExc_ValueError, buffer);
+		result = NULL;
 	}
-	result = PyFloat_FromDouble(x);
+
   error:
 	if (s_buffer)
 		PyMem_FREE(s_buffer);