diff --git a/suitesparse.spec b/suitesparse.spec
index 8964c51..0addf64 100644
--- a/suitesparse.spec
+++ b/suitesparse.spec
@@ -121,12 +121,15 @@ for fil in $(grep -Frl 'pragma ivdep' .); do
   rm -f ${fil}.orig
 done
 
+# drop non-standard -O3 and duplicate -fexceptions from default CFLAGS
+sed -i -e '/^  CF =/ s/ -O3 -fexceptions//' SuiteSparse_config/SuiteSparse_config.mk
+
 %build
 mkdir -p Doc/{AMD,BTF,CAMD,CCOLAMD,CHOLMOD,COLAMD,KLU,LDL,UMFPACK,SPQR,RBio} Lib Include
 
 # SuiteSparse_config needs to come first
 pushd SuiteSparse_config
-  make CFLAGS="$RPM_OPT_FLAGS -fPIC"
+  make CFLAGS="$RPM_OPT_FLAGS" %{?_smp_mflags}
   ar x libsuitesparseconfig.a
   pushd ../Lib
     gcc -shared %{?__global_ldflags} -Wl,-soname,libsuitesparseconfig.so.%{SuiteSparse_config_major} -o \
@@ -140,7 +143,7 @@ popd
 
 pushd AMD
   pushd Lib
-    make CFLAGS="$RPM_OPT_FLAGS -fPIC"
+    make CFLAGS="$RPM_OPT_FLAGS" %{?_smp_mflags}
   popd
   pushd ../Lib
     gcc -shared %{?__global_ldflags} -Wl,-soname,libamd.so.%{amd_version_major} -o \
@@ -156,7 +159,7 @@ popd
 
 pushd BTF
   pushd Lib
-    make CFLAGS="$RPM_OPT_FLAGS -fPIC"
+    make CFLAGS="$RPM_OPT_FLAGS" %{?_smp_mflags}
   popd
   pushd ../Lib
     gcc -shared %{?__global_ldflags} -Wl,-soname,libbtf.so.%{btf_version_major} -o \
@@ -171,7 +174,7 @@ popd
 
 pushd CAMD
   pushd Lib
-    make CFLAGS="$RPM_OPT_FLAGS -fPIC" 
+    make CFLAGS="$RPM_OPT_FLAGS" %{?_smp_mflags}
   popd
   pushd ../Lib
     gcc -shared %{?__global_ldflags} -Wl,-soname,libcamd.so.%{camd_version_major} -o \
@@ -187,7 +190,7 @@ popd
 
 pushd CCOLAMD
   pushd Lib
-    make CFLAGS="$RPM_OPT_FLAGS -fPIC" 
+    make CFLAGS="$RPM_OPT_FLAGS" %{?_smp_mflags}
   popd
   pushd ../Lib
     gcc -shared %{?__global_ldflags} -Wl,-soname,libccolamd.so.%{ccolamd_version_major} -o \
@@ -203,7 +206,7 @@ popd
 
 pushd COLAMD
   pushd Lib
-    make CFLAGS="$RPM_OPT_FLAGS -fPIC"
+    make CFLAGS="$RPM_OPT_FLAGS" %{?_smp_mflags}
   popd
   pushd ../Lib
     gcc -shared %{?__global_ldflags} -Wl,-soname,libcolamd.so.%{colamd_version_major} -o \
@@ -218,13 +221,13 @@ pushd COLAMD
 popd
 
 %if "%{?enable_metis}" == "1"
-CHOLMOD_FLAGS="$RPM_OPT_FLAGS -I%{_includedir}/metis -fPIC"
+CHOLMOD_FLAGS="$RPM_OPT_FLAGS -I%{_includedir}/metis"
 %else
-CHOLMOD_FLAGS="$RPM_OPT_FLAGS -DNPARTITION -fPIC"
+CHOLMOD_FLAGS="$RPM_OPT_FLAGS -DNPARTITION"
 %endif
 pushd CHOLMOD
   pushd Lib
-    make CFLAGS="$CHOLMOD_FLAGS"
+    make CFLAGS="$CHOLMOD_FLAGS" %{?_smp_mflags}
   popd
   pushd ../Lib
     gcc -shared %{?__global_ldflags} -Wl,-soname,libcholmod.so.%{cholmod_version_major} -o \
@@ -250,7 +253,7 @@ popd
 %if "%{?enable_csparse}" == "1"
 pushd CSparse
   pushd Source
-    make CFLAGS="$RPM_OPT_FLAGS -fPIC"
+    make CFLAGS="$RPM_OPT_FLAGS" %{?_smp_mflags}
     cp -p cs.h ../../Include
   popd
   pushd ../Lib
@@ -267,7 +270,7 @@ popd
 %else
 pushd CXSparse
   pushd Lib
-    make CFLAGS="$RPM_OPT_FLAGS -fPIC"
+    make CFLAGS="$RPM_OPT_FLAGS" %{?_smp_mflags}
   popd
   pushd ../Lib
     gcc -shared %{?__global_ldflags} -Wl,-soname,libcxsparse.so.%{cxsparse_version_major} -o \
@@ -284,7 +287,7 @@ popd
 
 pushd KLU
   pushd Lib
-    make CFLAGS="$RPM_OPT_FLAGS -fPIC"
+    make CFLAGS="$RPM_OPT_FLAGS" %{?_smp_mflags}
   popd
   pushd ../Lib
     gcc -shared %{?__global_ldflags} -Wl,-soname,libklu.so.%{klu_version_major} -o \
@@ -302,7 +305,7 @@ popd
 
 pushd LDL
   pushd Lib
-    make CFLAGS="$RPM_OPT_FLAGS -fPIC"
+    make CFLAGS="$RPM_OPT_FLAGS" %{?_smp_mflags}
   popd
   pushd ../Lib
     gcc -shared %{?__global_ldflags} -Wl,-soname,libldl.so.%{ldl_version_major} -o \
@@ -317,7 +320,7 @@ popd
 
 pushd UMFPACK
   pushd Lib
-    make CFLAGS="$RPM_OPT_FLAGS -fPIC" 
+    make CFLAGS="$RPM_OPT_FLAGS" %{?_smp_mflags}
   popd
   pushd ../Lib
     gcc -shared %{?__global_ldflags} -Wl,-soname,libumfpack.so.%{umfpack_version_major} -o \
@@ -336,7 +339,7 @@ popd
 
 pushd SPQR
   pushd Lib
-    make CFLAGS="$RPM_OPT_FLAGS -DHAVE_TBB -DNPARTITION -fPIC"
+    make CFLAGS="$RPM_OPT_FLAGS -DHAVE_TBB -DNPARTITION" %{?_smp_mflags}
   popd
   pushd ../Lib
     g++ -shared %{?__global_ldflags} -Wl,-soname,libspqr.so.%{spqr_version_major} -o \
@@ -356,7 +359,7 @@ popd
 
 pushd RBio
   pushd Lib
-    make CFLAGS="$RPM_OPT_FLAGS -fPIC"
+    make CFLAGS="$RPM_OPT_FLAGS" %{?_smp_mflags}
   popd
   pushd ../Lib
     gcc -shared %{?__global_ldflags} -Wl,-soname,librbio.so.%{rbio_version_major} -o \
@@ -421,6 +424,8 @@ hardlink -cv Docs/ Licenses/
 %changelog
 * Mon Jul 16 2018 Dominik Mierzejewski <rpm@greysector.net> - 4.4.6-14
 - use openblas instead of atlas (#1506933)
+- enable parallel make for faster builds and drop duplicate -fPIC
+- drop non-standard -O3 and duplicate -fexceptions from default CFLAGS
 
 * Sat Jul 14 2018 Fedora Release Engineering <releng@fedoraproject.org> - 4.4.6-13
 - Rebuilt for https://fedoraproject.org/wiki/Fedora_29_Mass_Rebuild