diff --git a/amanda-3.5.1-GCC10_extern.patch b/amanda-3.5.1-GCC10_extern.patch
new file mode 100644
index 0000000..ed11d45
--- /dev/null
+++ b/amanda-3.5.1-GCC10_extern.patch
@@ -0,0 +1,13 @@
+diff --git a/common-src/testutils.h b/common-src/testutils.h
+index 31f89737..2e9bb0b3 100644
+--- a/common-src/testutils.h
++++ b/common-src/testutils.h
+@@ -75,7 +75,7 @@ typedef struct TestUtilsTest {
+ #define tu_dbg(...) if (tu_debugging_enabled) { g_fprintf(stderr, __VA_ARGS__); }
+ 
+ /* Is debugging enabled for this test run? (set internally) */
+-int tu_debugging_enabled;
++extern gboolean tu_debugging_enabled;
+ 
+ /*
+  * Main loop
diff --git a/amanda.changes b/amanda.changes
index 8654a4e..5c24f6c 100644
--- a/amanda.changes
+++ b/amanda.changes
@@ -1,3 +1,8 @@
+-------------------------------------------------------------------
+Mon Jun  8 13:04:22 UTC 2020 - Kristyna Streitova <kstreitova@suse.com>
+
+- add amanda-3.5.1-GCC10_extern.patch to fix build with GCC10
+
 -------------------------------------------------------------------
 Thu Nov 28 15:25:56 UTC 2019 - Kristyna Streitova <kstreitova@suse.com>
 
diff --git a/amanda.spec b/amanda.spec
index cb3380a..f489010 100644
--- a/amanda.spec
+++ b/amanda.spec
@@ -1,7 +1,7 @@
 #
 # spec file for package amanda
 #
-# Copyright (c) 2019 SUSE LINUX GmbH, Nuernberg, Germany.
+# Copyright (c) 2020 SUSE LLC
 #
 # All modifications and additions to the file contributed by third parties
 # remain the property of their copyright owners, unless otherwise agreed
@@ -34,6 +34,7 @@ Patch4:         amanda-3.3.2-returnvalues.patch
 Patch5:         amanda-timestamp.patch
 Patch6:         amanda-3.5-no_return_in_nonvoid_fnc.patch
 Patch7:         amanda-libnsl.patch
+Patch8:         amanda-3.5.1-GCC10_extern.patch
 BuildRequires:  autoconf
 BuildRequires:  automake
 BuildRequires:  bison
@@ -90,6 +91,7 @@ rm -r patches
 %patch5 -p1
 %patch6 -p1
 %patch7 -p1
+%patch8 -p1
 
 %build
 ./autogen