diff --git a/CHANGES b/CHANGES
index 884c1d0..df35179 100644
--- a/CHANGES
+++ b/CHANGES
@@ -36,6 +36,7 @@ Modules/
 * Fix memory leak in whoami
 * Fix internal error handling of LDAPControl_to_List()
 * Fix two memory leaks and release GIL in encode_assertion_control
+* Allow set_option() to set timeouts to infinity
 and, thanks to Michael Ströder:
 * removed unused code schema.c
 * moved code from version.c to ldapmodule.c
diff --git a/Doc/reference/ldap.rst b/Doc/reference/ldap.rst
index c28cdec..1f7ae5b 100644
--- a/Doc/reference/ldap.rst
+++ b/Doc/reference/ldap.rst
@@ -156,6 +156,9 @@ following option identifiers are defined as constants:
 
 .. py:data:: OPT_NETWORK_TIMEOUT
 
+   .. versionchanged:: 3.0
+      A timeout of ``-1`` resets timeout to infinity.
+
 .. py:data:: OPT_PROTOCOL_VERSION
 
    Sets the LDAP protocol version used for a connection. This is mapped to
@@ -180,6 +183,9 @@ following option identifiers are defined as constants:
 
 .. py:data:: OPT_TIMEOUT
 
+   .. versionchanged:: 3.0
+      A timeout of ``-1`` resets timeout to infinity.
+
 .. py:data:: OPT_URI
 
 .. _ldap-sasl-options:
diff --git a/Modules/options.c b/Modules/options.c
index f5bae42..647f859 100644
--- a/Modules/options.c
+++ b/Modules/options.c
@@ -140,10 +140,20 @@ LDAP_set_option(LDAPObject *self, int option, PyObject *value)
 	    if (!PyArg_Parse(value, "d:set_option", &doubleval))
 		return 0;
             if (doubleval >= 0) {
-	        set_timeval_from_double( &tv, doubleval );
+                set_timeval_from_double( &tv, doubleval );
+                ptr = &tv;
+            } else if (doubleval == -1) {
+                /* -1 is infinity timeout */
+                tv.tv_sec = -1;
+                tv.tv_usec = 0;
                 ptr = &tv;
             } else {
-    	        ptr = NULL;
+                PyErr_Format(
+                    PyExc_ValueError,
+                    "timeout must be >= 0 or -1 for infinity, got %d",
+                    option
+                );
+                return 0;
             }
 	    break;
     case LDAP_OPT_SERVER_CONTROLS: