diff --git a/Compiler/openmpi/build b/Compiler/openmpi/build
index 727527e..52f47b1 100755
--- a/Compiler/openmpi/build
+++ b/Compiler/openmpi/build
@@ -24,8 +24,9 @@ pbuild::pre_configure() {
 	pbuild::add_configure_args "--enable-static"
        	pbuild::add_configure_args "--with-hwloc=internal"
 	pbuild::add_configure_args "--with-slurm=yes"
-	pbuild::add_configure_args "--with-ucx=${UCX_PREFIX}"
-
+	if [[ -n "${UCX_VERSION}" ]]; then
+		pbuild::add_configure_args "--with-ucx=${UCX_PREFIX}"
+	fi
         if pbuild::use_flag slurm || pbuild::use_flag dgx || pbuild::use_flag merlin6; then
 		pbuild::add_configure_args "--with-pmi"
 		pbuild::add_configure_args "--with-pmi-libdir=/usr/lib64/"
diff --git a/Compiler/openmpi/files/variants.merlin6 b/Compiler/openmpi/files/variants.merlin6
index b522467..d6fd475 100644
--- a/Compiler/openmpi/files/variants.merlin6
+++ b/Compiler/openmpi/files/variants.merlin6
@@ -28,7 +28,7 @@ openmpi/4.0.5_slurm     stable     gcc/9.2.0 cuda/11.0.3
 openmpi/4.0.5_slurm     stable     gcc/{8.4.0,9.3.0} cuda/11.1.0
 openmpi/4.0.5_slurm     stable     intel/20.4 cuda/11.1.0
 
-openmpi/4.0.5-1_slurm   stable     gcc/{8.4.0,9.3.0,10.2.0} cuda/11.2.2 b:ucx/1.10.0-1_slurm
+openmpi/4.0.5-1_slurm   stable     gcc/{8.4.0,9.3.0,10.2.0,10.3.0} cuda/11.2.2 b:ucx/1.10.0-1_slurm
 openmpi/4.0.5-2_slurm   unstable   gcc/10.2.0 cuda/11.3.0 b:ucx/1.11.0_slurm
 
 openmpi/4.0.5-1_dgx     deprecated gcc/{8.4.0,9.3.0,10.2.0} cuda/11.2.2 b:ucx/1.10.0-1_dgx
diff --git a/Compiler/openmpi/files/variants.rhel6 b/Compiler/openmpi/files/variants.rhel6
index e99a64a..611d48a 100644
--- a/Compiler/openmpi/files/variants.rhel6
+++ b/Compiler/openmpi/files/variants.rhel6
@@ -40,10 +40,13 @@ openmpi/3.1.2	deprecated	intel/18.4
 openmpi/3.1.3	deprecated	gcc/{4.8.5,5.5.0,6.4.0,6.5.0,7.3.0,8.2.0,8.3.0}
 openmpi/3.1.4   deprecated	gcc/{7.4.0,8.3.0,9.1.0,9.2.0}
 
-openmpi/3.1.6	stable		gcc/{7.5.0,8.4.0,9.3.0,10.1.0}
+openmpi/3.1.6	stable		gcc/{7.5.0,8.4.0,9.3.0,10.1.0,10.3.0}
 
 openmpi/4.0.0	stable		gcc/{5.5,6.4,6.5,7.3,7.4,8.2,8.3}.0
 
 openmpi/4.0.1   stable		gcc/7.4.0
 
-openmpi/4.0.5   unstable	gcc/{7.5.0,8.4.0,9.3.0,10.2.0} ucx/1.8.1
+openmpi/4.0.2	stable		gcc/9.2.0
+
+openmpi/4.0.5   stable		gcc/{7.5.0,8.4.0,9.3.0,10.2.0} ucx/1.8.1
+openmpi/4.0.5   stable		gcc/10.3.0