diff --git a/inkscape-gcc11.patch b/inkscape-gcc11.patch
new file mode 100644
index 0000000..71af717
--- /dev/null
+++ b/inkscape-gcc11.patch
@@ -0,0 +1,22 @@
+diff --git a/src/extension/system.cpp b/src/extension/system.cpp
+index 08de0b4..9ba73a1 100644
+--- a/src/extension/system.cpp
++++ b/src/extension/system.cpp
+@@ -174,7 +174,7 @@ open_internal(Extension *in_plug, gpointer in_data)
+         // skip all the rest if we already found a function to open it
+         // since they're ordered by preference now.
+         if (!*pimod) {
+-            gchar const *ext = dynamic_cast<Input *>(in_plug)->get_extension();
++            gchar const *ext = dynamic_cast<Input &>(*in_plug).get_extension();
+ 
+             gchar *filenamelower = g_utf8_strdown(filename, -1);
+             gchar *extensionlower = g_utf8_strdown(ext, -1);
+@@ -384,7 +384,7 @@ save_internal(Extension *in_plug, gpointer in_data)
+         // skip all the rest if we already found someone to save it
+         // since they're ordered by preference now.
+         if (!*pomod) {
+-            gchar const *ext = dynamic_cast<Output *>(in_plug)->get_extension();
++            gchar const *ext = dynamic_cast<Output &>(*in_plug).get_extension();
+ 
+             gchar *filenamelower = g_utf8_strdown(filename, -1);
+             gchar *extensionlower = g_utf8_strdown(ext, -1);
diff --git a/inkscape.spec b/inkscape.spec
index 4b5238b..f19020b 100644
--- a/inkscape.spec
+++ b/inkscape.spec
@@ -2,7 +2,7 @@
 
 Name:           inkscape
 Version:        1.0
-Release:        7%{?dist}
+Release:        8%{?dist}
 Summary:        Vector-based drawing program using SVG
 
 # Inkscape tags their releases with underscores and in ALLCAPS
@@ -15,6 +15,8 @@ Source0:        https://inkscape.org/gallery/item/18460/inkscape-1.0_2020-05-01_
 # Fedora Color Palette, GIMP format, CC-BY 3.0
 Source2:	Fedora-Color-Palette.gpl
 
+Patch1:         inkscape-gcc11.patch
+
 Provides: bundled(libcroco)
 Provides: bundled(libgdl)
 
@@ -220,6 +222,9 @@ desktop-file-validate $RPM_BUILD_ROOT%{_datadir}/applications/org.inkscape.Inksc
 
 
 %changelog
+* Thu Sep 03 2020 Jeff Law <law@redhat.com> - 1.0-8
+- Refine dynamic casts to avoid -Wnonnull warning with gcc-11
+
 * Mon Aug 17 2020 Kalev Lember <klember@redhat.com> - 1.0-7
 - Drop two unneeded dependencies
 - Validate appdata file in check rather than install section