diff --git a/vtk-compat_gl.changes b/vtk-compat_gl.changes
index 090735f..3f97b51 100644
--- a/vtk-compat_gl.changes
+++ b/vtk-compat_gl.changes
@@ -1,3 +1,8 @@
+-------------------------------------------------------------------
+Wed Aug  9 08:54:55 UTC 2017 - jengelh@inai.de
+
+- Fix RPM groups. Use POSIX-compliant find call.
+
 -------------------------------------------------------------------
 Mon Aug  7 09:13:03 UTC 2017 - badshah400@gmail.com
 
diff --git a/vtk-compat_gl.spec b/vtk-compat_gl.spec
index af23966..34295b0 100644
--- a/vtk-compat_gl.spec
+++ b/vtk-compat_gl.spec
@@ -125,8 +125,8 @@ rendering techniques (e.g. hardware-accelerated volume rendering, LOD
 control).
 
 %package -n %{shlib}
-Summary:        Shared libraries for %{pkgname}
-Group:          Productivity/Scientific/Other
+Summary:        The Visualization Toolkit - A high level 3D visualization library
+Group:          System/Libraries
 %if %{compat_gl}
 Conflicts:      %{vtklib}
 %else
@@ -234,7 +234,7 @@ This package provides Qt bindings for VTK.
 
 %package tcl
 Summary:        Tcl bindings for VTK
-Group:          System/Libraries
+Group:          Development/Languages/Tcl
 Requires:       %{shlib} = %{version}
 %if %{compat_gl}
 Conflicts:      vtk-tcl
@@ -293,7 +293,7 @@ This package provides a few testing programs for VTK.
 
 # Replace relative path ../../../VTKData with %%{_datadir}/%%{pkgname}data-%%{version}
 # otherwise it will break on symlinks.
-grep -rl '\.\./\.\./\.\./\.\./VTKData' . | xargs perl -pi -e's,\.\./\.\./\.\./\.\./VTKData,%{_datadir}/%{pkgname},g'
+grep -rl '\.\./\.\./\.\./\.\./VTKData' . | xargs -r perl -pi -e's,\.\./\.\./\.\./\.\./VTKData,%{_datadir}/%{pkgname},g'
 
 %build
 export CFLAGS="%{optflags}"
@@ -359,7 +359,7 @@ make %{?_smp_mflags} VERBOSE=1
 make %{?_smp_mflags} DoxygenDoc
 
 # Remove executable bits from sources (some of which are generated)
-find . -name \*.c -or -name \*.cxx -or -name \*.h -or -name \*.hxx -or -name \*.gif | xargs chmod -x
+find . -name \*.c -o -name \*.cxx -o -name \*.h -o -name \*.hxx -o -name \*.gif -exec chmod -x "{}" "+"
 popd
 
 %install
diff --git a/vtk.changes b/vtk.changes
index 090735f..3f97b51 100644
--- a/vtk.changes
+++ b/vtk.changes
@@ -1,3 +1,8 @@
+-------------------------------------------------------------------
+Wed Aug  9 08:54:55 UTC 2017 - jengelh@inai.de
+
+- Fix RPM groups. Use POSIX-compliant find call.
+
 -------------------------------------------------------------------
 Mon Aug  7 09:13:03 UTC 2017 - badshah400@gmail.com
 
diff --git a/vtk.spec b/vtk.spec
index 2ade832..0ca01c8 100644
--- a/vtk.spec
+++ b/vtk.spec
@@ -125,8 +125,8 @@ rendering techniques (e.g. hardware-accelerated volume rendering, LOD
 control).
 
 %package -n %{shlib}
-Summary:        Shared libraries for %{pkgname}
-Group:          Productivity/Scientific/Other
+Summary:        The Visualization Toolkit - A high level 3D visualization library
+Group:          System/Libraries
 %if %{compat_gl}
 Conflicts:      %{vtklib}
 %else
@@ -234,7 +234,7 @@ This package provides Qt bindings for VTK.
 
 %package tcl
 Summary:        Tcl bindings for VTK
-Group:          System/Libraries
+Group:          Development/Languages/Tcl
 Requires:       %{shlib} = %{version}
 %if %{compat_gl}
 Conflicts:      vtk-tcl
@@ -293,7 +293,7 @@ This package provides a few testing programs for VTK.
 
 # Replace relative path ../../../VTKData with %%{_datadir}/%%{pkgname}data-%%{version}
 # otherwise it will break on symlinks.
-grep -rl '\.\./\.\./\.\./\.\./VTKData' . | xargs perl -pi -e's,\.\./\.\./\.\./\.\./VTKData,%{_datadir}/%{pkgname},g'
+grep -rl '\.\./\.\./\.\./\.\./VTKData' . | xargs -r perl -pi -e's,\.\./\.\./\.\./\.\./VTKData,%{_datadir}/%{pkgname},g'
 
 %build
 export CFLAGS="%{optflags}"
@@ -359,7 +359,7 @@ make %{?_smp_mflags} VERBOSE=1
 make %{?_smp_mflags} DoxygenDoc
 
 # Remove executable bits from sources (some of which are generated)
-find . -name \*.c -or -name \*.cxx -or -name \*.h -or -name \*.hxx -or -name \*.gif | xargs chmod -x
+find . -name \*.c -o -name \*.cxx -o -name \*.h -o -name \*.hxx -o -name \*.gif -exec chmod -x "{}" "+"
 popd
 
 %install