diff --git a/cppad.spec b/cppad.spec
index b398978..88e1464 100644
--- a/cppad.spec
+++ b/cppad.spec
@@ -86,6 +86,18 @@ mv CppAD-%{yyyymmdd}.doc/doc CppAD-%{version}/doc
 mv CppAD-%{version}/COPYING  COPYING
 mv CppAD-%{version}/uw_copy_040507.html uw_copy_040507.html
 #
+# Patch corresponding to bug fix in unstream source 20210000.4
+cp CppAD-%{version}/include/cppad/core/abs_normal_fun.hpp \
+    CppAD-%{version}/include/cppad/core/abs_normal_fun.bak
+for uu in vp pv vv
+do
+        sed -i CppAD-%{version}/include/cppad/core/abs_normal_fun.hpp \
+            -e "/ Zmul${uu}Op/N" \
+            -e "/ Zmul${uu}Op/s|\n *CPPAD_ASSERT_NARG_NRES(op, 2, 1);||"
+done
+sed -i CppAD-%{version}/include/cppad/core/abs_normal_fun.hpp \
+    -e 's|^\( *\)case ZmulvvOp:|\1case PowvvOp:\n&|'
+#
 # cppad_lib: replace soversion number and ensure build type is release 
 sed -i.bak CppAD-%{version}/cppad_lib/CMakeLists.txt \
     -e "s|print_variable(soversion)|SET(soversion %{soversion} )\n&|" \
@@ -183,6 +195,8 @@ make %{?_smp_mflags} check
 
 # ----------------------------------------------------------------------------
 %changelog
+* Tue Feb 02 2021 Brad Bell <bradbell at seanet dot com> - 20210000.3-2
+- Patch corresponding to bug fix in upstream source 20210000.4
 
 * Tue Jan 26 2021 Brad Bell <bradbell at seanet dot com> - 20210000.3-1
 - Advance to upstream source 20210000.3