diff --git a/CI/scripts/synth_designs.sh b/CI/scripts/synth_designs.sh
index fc741cd6..cea5816f 100644
--- a/CI/scripts/synth_designs.sh
+++ b/CI/scripts/synth_designs.sh
@@ -17,7 +17,7 @@ sed -i "s/hdlcoder_board_customization/hdlcoder_board_customization_local/g" tes
 source /opt/Xilinx/Vivado/2022.2/settings64.sh
 # Randomize DISPLAY number to avoid conflicts
 export DISPLAY_ID=:$(shuf -i 10-1000 -n 1)
-Xvfb :$DISPLAY_ID &
+Xvfb $DISPLAY_ID &
 XVFB_PID=$!
 export DISPLAY=$DISPLAY_ID
 export SWT_GTK3=0
diff --git a/CI/scripts/targeting_designs.sh b/CI/scripts/targeting_designs.sh
index acd93015..1c6eb205 100644
--- a/CI/scripts/targeting_designs.sh
+++ b/CI/scripts/targeting_designs.sh
@@ -19,7 +19,7 @@ cd ../..
 source /opt/Xilinx/Vivado/2022.2/settings64.sh
 # Randomize DISPLAY number to avoid conflicts
 export DISPLAY_ID=:$(shuf -i 10-1000 -n 1)
-Xvfb :$DISPLAY_ID &
+Xvfb $DISPLAY_ID &
 XVFB_PID=$!
 export DISPLAY=$DISPLAY_ID
 export SWT_GTK3=0