diff --git a/libxml++.spec b/libxml++.spec
index aea8158..538bc12 100644
--- a/libxml++.spec
+++ b/libxml++.spec
@@ -24,7 +24,7 @@ and Murray Cumming.
 %package devel
 Summary:        Development files for %{name}
 Group:          Development/Libraries
-Requires:       %{name} = %{version}-%{release}
+Requires:       %{name}%{?_isa} = %{version}-%{release}
 Requires:       libxml2-devel
 Requires:       glibmm24-devel
 
@@ -86,6 +86,7 @@ sed -i "s#$RPM_BUILD_ROOT##g" \
 %changelog
 * Mon Sep 21 2015 Kalev Lember <klember@redhat.com> - 2.40.0-1
 - Update to 2.40.0
+- Tighten -devel subpackage deps with _isa macro
 
 * Wed Jun 17 2015 Fedora Release Engineering <rel-eng@lists.fedoraproject.org> - 2.38.1-2
 - Rebuilt for https://fedoraproject.org/wiki/Fedora_23_Mass_Rebuild