diff --git a/0001-Properly-encode-OAuth2-credentials.patch b/0001-Properly-encode-OAuth2-credentials.patch
new file mode 100644
index 0000000..88a0da6
--- /dev/null
+++ b/0001-Properly-encode-OAuth2-credentials.patch
@@ -0,0 +1,76 @@
+From 8406c694eb58e610fbf94eba00719e097bad34d8 Mon Sep 17 00:00:00 2001
+From: Stephan Bergmann <sbergman@redhat.com>
+Date: Tue, 4 Sep 2018 17:14:21 +0200
+Subject: [PATCH] Properly encode OAuth2 credentials
+
+Originally created as <https://gerrit.libreoffice.org/#/c/59986/> "Properly
+encode OAuth2 credentials".  I was not sure which C++ version to target, so kept
+it pretty basic.
+---
+ src/libcmis/oauth2-providers.cxx | 29 +++++++++++++++++++++++++++--
+ 1 file changed, 27 insertions(+), 2 deletions(-)
+
+diff --git a/src/libcmis/oauth2-providers.cxx b/src/libcmis/oauth2-providers.cxx
+index dd872dd..c14438f 100644
+--- a/src/libcmis/oauth2-providers.cxx
++++ b/src/libcmis/oauth2-providers.cxx
+@@ -26,6 +26,8 @@
+  * instead of those above.
+  */
+ 
++#include <cassert>
++
+ #include <libxml/HTMLparser.h>
+ #include <libxml/xmlreader.h>
+ 
+@@ -41,6 +43,29 @@
+ 
+ using namespace std;
+ 
++namespace {
++
++// See <https://url.spec.whatwg.org/#concept-urlencoded-byte-serializer>:
++void addXWwwFormUrlencoded(std::string * buffer, std::string const & data) {
++    assert(buffer);
++    for (string::const_iterator i = data.begin(); i != data.end(); ++i) {
++        unsigned char c = static_cast<unsigned char>(*i);
++        if (c == ' ' || c == '*' || c == '-' || c == '.' || (c >= '0' && c <= '9')
++            || (c >= 'A' && c <= 'Z') || c == '_' || (c >= 'a' && c <= 'z'))
++        {
++            *buffer += static_cast<char>(c);
++        } else {
++            static const char hex[16] = {
++                '0', '1', '2', '3', '4', '5', '6', '7', '8', '9', 'A', 'B', 'C', 'D', 'E', 'F'};
++            *buffer += '%';
++            *buffer += hex[c >> 4];
++            *buffer += hex[c & 0xF];
++        }
++    }
++}
++
++}
++
+ string OAuth2Providers::OAuth2Gdrive( HttpSession* session, const string& authUrl,
+                                       const string& username, const string& password )
+ {
+@@ -93,7 +118,7 @@ string OAuth2Providers::OAuth2Gdrive( HttpSession* session, const string& authUr
+         return string( );
+ 
+     loginEmailPost += "Email=";
+-    loginEmailPost += string( username );
++    addXWwwFormUrlencoded(&loginEmailPost, username);
+ 
+     istringstream loginEmailIs( loginEmailPost );
+     string loginEmailRes;
+@@ -115,7 +140,7 @@ string OAuth2Providers::OAuth2Gdrive( HttpSession* session, const string& authUr
+         return string( );
+ 
+     loginPasswdPost += "Passwd=";
+-    loginPasswdPost += string( password );
++    addXWwwFormUrlencoded(&loginPasswdPost, password);
+ 
+     istringstream loginPasswdIs( loginPasswdPost );
+     string loginPasswdRes;
+-- 
+2.17.1
+
diff --git a/libcmis.spec b/libcmis.spec
index 915175c..1b7ff11 100644
--- a/libcmis.spec
+++ b/libcmis.spec
@@ -2,7 +2,7 @@
 
 Name: libcmis
 Version: 0.5.1
-Release: 12%{?dist}
+Release: 13%{?dist}
 Summary: A C/C++ client library for CM interfaces
 
 License: GPLv2+ or LGPLv2+ or MPLv1.1
@@ -27,6 +27,7 @@ Patch5: 0001-update-boost.m4-to-fix-version-detection-with-gcc-6..patch
 Patch6: 0001-rhbz-1410197-limit-the-number-of-redirections.patch
 Patch7: 0001-do-not-try-to-use-on-an-empty-string.patch
 Patch8: 0002-return-early-if-the-time-part-is-empty.patch
+Patch9: 0001-Properly-encode-OAuth2-credentials.patch
 
 %description
 LibCMIS is a C/C++ client library for working with CM (content management)
@@ -96,6 +97,9 @@ make %{?_smp_mflags} check
 %{_mandir}/man1/cmis-client.1*
 
 %changelog
+* Wed Sep 12 2018 Stephan Bergmann <sbergman@redhat.com> - 0.5.1-13
+- fix Google Drive login
+
 * Fri Jul 13 2018 Fedora Release Engineering <releng@fedoraproject.org> - 0.5.1-12
 - Rebuilt for https://fedoraproject.org/wiki/Fedora_29_Mass_Rebuild