diff --git a/restsharp.spec b/restsharp.spec
index 967d19b..26b03d6 100644
--- a/restsharp.spec
+++ b/restsharp.spec
@@ -5,7 +5,7 @@
 
 Name:           restsharp
 Version:        105.2.3
-Release:        19%{?dist}
+Release:        20%{?dist}
 Summary:        Simple REST and HTTP API Client
 
 # Main license is Apache 2.0, but MIT/X11 for Extensions/MonoHttp and SimpleJson
@@ -23,6 +23,10 @@ BuildRequires:  nunit2 = 2.6.4
 
 ExclusiveArch: %{mono_arches}
 
+# nunit2 fails to build on armv7hl. Mono crashes. see bug 1923663
+# it is too much work to switch to nunit (version 3) at the moment.
+ExcludeArch:    armv7hl
+
 %description
 %{summary}.
 
@@ -92,6 +96,9 @@ nunit-console26 -labels -stoponerror bin/Debug/%{libname}.Tests.dll
 
 
 %changelog
+* Thu Aug 05 2021 Timotheus Pokorra <timotheus.pokorra@solidcharity.com> - 105.2.3-20
+- disable arch armv7hl
+
 * Fri Jul 23 2021 Fedora Release Engineering <releng@fedoraproject.org> - 105.2.3-19
 - Rebuilt for https://fedoraproject.org/wiki/Fedora_35_Mass_Rebuild