diff --git a/libvmime.changes b/libvmime.changes
index 43b6ddf..4bf0c39 100644
--- a/libvmime.changes
+++ b/libvmime.changes
@@ -1,3 +1,9 @@
+-------------------------------------------------------------------
+Mon Apr 23 07:58:00 UTC 2018 - jengelh@inai.de
+
+- Add no-override-cflags.diff so that vmime becomes externally
+  buildable with other -O/-g levels.
+
 -------------------------------------------------------------------
 Thu Jul 13 14:11:54 UTC 2017 - jengelh@inai.de
 
diff --git a/libvmime.spec b/libvmime.spec
index bad2526..eee0353 100644
--- a/libvmime.spec
+++ b/libvmime.spec
@@ -1,7 +1,7 @@
 #
 # spec file for package libvmime
 #
-# Copyright (c) 2013 SUSE LINUX Products GmbH, Nuernberg, Germany.
+# Copyright (c) 2018 SUSE LINUX GmbH, Nuernberg, Germany.
 #
 # All modifications and additions to the file contributed by third parties
 # remain the property of their copyright owners, unless otherwise agreed
@@ -19,7 +19,7 @@
 Name:           libvmime
 %define lname	libvmime1
 Summary:        Library for working with RFC 2822, MIME messages and IMAP/POP/SMTP
-License:        GPL-3.0+
+License:        GPL-3.0-or-later
 Group:          Development/Libraries/C and C++
 Version:        0.9.2
 Release:        0
@@ -27,6 +27,7 @@ Url:            http://vmime.org/
 
 Source:         https://github.com/kisli/vmime/archive/v%version.tar.gz
 Patch1:         libvmime-nodatetime.diff
+Patch2:         no-override-cflags.diff
 BuildRoot:      %{_tmppath}/%{name}-%{version}-build
 BuildRequires:  ImageMagick
 %if 0%{?suse_version} < 1310
@@ -93,7 +94,7 @@ This subpackage contains the headers for the library's API.
 
 %prep
 %setup -qn vmime-%version
-%patch -P 1 -p1
+%patch -P 1 -P 2 -p1
 
 %build
 %if 0%{?with_pdf}
@@ -113,7 +114,6 @@ cmake . \
 	-DVMIME_BUILD_STATIC_LIBRARY:BOOL=OFF \
 	-DCMAKE_BUILD_TYPE:STRING="RelWithDebInfo" \
 	-DCMAKE_INSTALL_PREFIX:PATH="%_prefix" \
-	-DCMAKE_CXX_FLAGS_DEBUG:STRING="-g" \
 %if 0%{?suse_version} >= 1310
 	-DCMAKE_CXX_FLAGS:STRING="$cf -std=gnu++11" \
 %else
diff --git a/no-override-cflags.diff b/no-override-cflags.diff
new file mode 100644
index 0000000..1d08279
--- /dev/null
+++ b/no-override-cflags.diff
@@ -0,0 +1,28 @@
+From: Jan Engelhardt <jengelh@inai.de>
+Date: 2018-04-23 09:57:31.270364598 +0200
+References: https://github.com/kisli/vmime/issues/196
+
+Do not tack on any -O/-g flags at the end of the command line,
+as that negates any that we got from %optflags.
+
+---
+ CMakeLists.txt |    6 +++---
+ 1 file changed, 3 insertions(+), 3 deletions(-)
+
+Index: vmime-0.9.2/CMakeLists.txt
+===================================================================
+--- vmime-0.9.2.orig/CMakeLists.txt
++++ vmime-0.9.2/CMakeLists.txt
+@@ -1050,9 +1050,9 @@ ELSE()
+ 			"${CMAKE_CXX_FLAGS} -D_REENTRANT=1 -W -Wall -pedantic -Wpointer-arith -Wold-style-cast -Wconversion -Wcast-align -Wno-long-long"
+ 		)
+ 
+-		SET(CMAKE_CXX_FLAGS_RELEASE "-O2")
+-		SET(CMAKE_CXX_FLAGS_DEBUG "-O0 -g")
+-		SET(CMAKE_CXX_FLAGS_RELWITHDEBINFO "-O2 -g")
++		SET(CMAKE_CXX_FLAGS_RELEASE "")
++		SET(CMAKE_CXX_FLAGS_DEBUG "")
++		SET(CMAKE_CXX_FLAGS_RELWITHDEBINFO "")
+ 
+ 		#SET(CMAKE_EXE_LINKER_FLAGS "-s")
+