diff --git a/embree.spec b/embree.spec
index b672cc4..b3781b1 100644
--- a/embree.spec
+++ b/embree.spec
@@ -1,6 +1,6 @@
 Name:          embree
 Version:       4.3.1
-Release:       1mamba
+Release:       2mamba
 Summary:       A collection of high-performance ray tracing kernels, developed at Intel
 Group:         System/Libraries
 Vendor:        openmamba
@@ -16,6 +16,7 @@ BuildRequires: libstdc++6-devel
 BuildRequires: libtbb-devel
 ## AUTOBUILDREQ-END
 BuildRequires: cmake
+BuildRequires: ispc
 Requires:      lib%{name} = %{?epoch:%epoch:}%{version}-%{release}
 
 %description
@@ -37,7 +38,6 @@ Requires:      lib%{name} = %{?epoch:%epoch:}%{version}-%{release}
 %description -n lib%{name}-devel
 This package contains libraries and header files for developing applications that use %{name}.
 
-
 %debug_package
 
 %prep
@@ -45,7 +45,7 @@ This package contains libraries and header files for developing applications tha
 
 %build
 %cmake -d build \
-   -DEMBREE_ISPC_SUPPORT=OFF \
+   -DEMBREE_ISPC_SUPPORT=ON \
    -DEMBREE_TUTORIALS=OFF \
 %ifarch x86_64 %{ix86}
    -DEMBREE_MAX_ISA="AVX512SKX" \
@@ -85,6 +85,9 @@ rm -f %{buildroot}%{_prefix}/embree-vars.*
 %{_libdir}/cmake/embree-%{version}/embree*.cmake
 
 %changelog
+* Sat May 04 2024 Silvan Calarco <silvan.calarco@mambasoft.it> 4.3.1-2mamba
+- rebuilt with ispc and EMBREE_ISPC_SUPPORT=ON
+
 * Mon Feb 12 2024 Automatic Build System <autodist@openmamba.org> 4.3.1-1mamba
 - automatic version update by autodist