diff --git a/passes/sat/sat.cc b/passes/sat/sat.cc
index e5f678820..60be79d62 100644
--- a/passes/sat/sat.cc
+++ b/passes/sat/sat.cc
@@ -216,7 +216,7 @@ struct SatHelper
 
 		int import_cell_counter = 0;
 		for (auto &c : module->cells)
-			if (design->selected(module, c.second) && ct.cell_known(c.second->type)) {
+			if (design->selected(module, c.second)) {
 				// log("Import cell: %s\n", RTLIL::id2cstr(c.first));
 				if (satgen.importCell(c.second, timestep)) {
 					for (auto &p : c.second->connections)
diff --git a/tests/xsthammer/run-check.sh b/tests/xsthammer/run-check.sh
index 6a77e2367..b2d9193ae 100644
--- a/tests/xsthammer/run-check.sh
+++ b/tests/xsthammer/run-check.sh
@@ -9,12 +9,12 @@ job="$1"
 set --
 
 set -e
-mkdir -p check check_temp
-cd check_temp
+mkdir -p check check_temp/$job
+cd check_temp/$job
 
 {
 	echo "module ${job}_top(a, b, y_rtl, y_xst);"
-	sed -r '/^(input|output) / !d; /output/ { s/ y;/ y_rtl;/; p; }; s/ y_rtl;/ y_xst;/;' ../rtl/$job.v
+	sed -r '/^(input|output) / !d; /output/ { s/ y;/ y_rtl;/; p; }; s/ y_rtl;/ y_xst;/;' ../../rtl/$job.v
 	echo "${job}_rtl rtl_variant (.a(a), .b(b), .y(y_rtl));"
 	echo "${job}_xst xst_variant (.a(a), .b(b), .y(y_xst));"
 	echo "endmodule"
@@ -22,17 +22,17 @@ cd check_temp
 
 for mode in nomap techmap; do
 	{
-		echo "read_verilog -DGLBL ../xst/$job.v"
+		echo "read_verilog -DGLBL ../../xst/$job.v"
 		echo "rename $job ${job}_xst"
 
-		echo "read_verilog ../rtl/$job.v"
+		echo "read_verilog ../../rtl/$job.v"
 		echo "rename $job ${job}_rtl"
 		if [ $mode = techmap ]; then
 			echo "techmap ${job}_rtl"
 		fi
 
 		echo "read_verilog ${job}_top.v"
-		echo "read_verilog ../xl_cells.v"
+		echo "read_verilog ../../xl_cells.v"
 
 		echo "hierarchy -top ${job}_top"
 		echo "flatten ${job}_top"
@@ -42,7 +42,7 @@ for mode in nomap techmap; do
 		echo "rename ${job}_top ${job}_top_${mode}"
 		echo "write_ilang ${job}_top_${mode}.il"
 	} > ${job}_top_${mode}.ys
-	../../../yosys -q ${job}_top_${mode}.ys
+	../../../../yosys -q ${job}_top_${mode}.ys
 done
 
 {
@@ -52,12 +52,12 @@ done
 	echo "sat -verify -show a,b,y_rtl,y_xst -prove y_rtl y_xst ${job}_top_techmap"
 } > ${job}_cmp.ys
 
-if ../../../yosys -l ${job}.log ${job}_cmp.ys; then
-	mv ${job}.log ../check/${job}.log
-	rm -f ../check/${job}.err
+if ../../../../yosys -l ${job}.log ${job}_cmp.ys; then
+	mv ${job}.log ../../check/${job}.log
+	rm -f ../../check/${job}.err
 else
-	mv ${job}.log ../check/${job}.err
-	rm -f ../check/${job}.log
+	mv ${job}.log ../../check/${job}.err
+	rm -f ../../check/${job}.log
 	exit 1
 fi
 
diff --git a/tests/xsthammer/run-xst.sh b/tests/xsthammer/run-xst.sh
index 216707072..b421e2954 100644
--- a/tests/xsthammer/run-xst.sh
+++ b/tests/xsthammer/run-xst.sh
@@ -14,59 +14,16 @@ cd xst_temp/$job
 
 cat > $job.xst <<- EOT
 	run
-	-ifn $job.prj
-	-ifmt mixed
-	-ofn $job
-	-ofmt NGC
-	-p xc6vlx75t-2-ff784
-	-top $job
-	-opt_mode Speed
-	-opt_level 1
-	-power NO
-	-iuc NO
-	-keep_hierarchy NO
-	-rtlview Yes
-	-glob_opt AllClockNets
-	-read_cores YES
-	-write_timing_constraints NO
-	-cross_clock_analysis NO
-	-hierarchy_separator /
-	-bus_delimiter <>
-	-case maintain
-	-slice_utilization_ratio 100
-	-bram_utilization_ratio 100
-	-dsp_utilization_ratio 100
+	-ifn $job.prj -ofn $job -p artix7 -top $job
+	-iobuf NO -ram_extract NO -rom_extract NO -use_dsp48 NO
 	-fsm_extract YES -fsm_encoding Auto
-	-safe_implementation No
-	-fsm_style lut
-	-ram_extract Yes
-	-ram_style Auto
-	-rom_extract Yes
-	-shreg_extract YES
-	-rom_style Auto
-	-auto_bram_packing NO
-	-resource_sharing YES
-	-async_to_sync NO
-	-use_dsp48 auto
-	-iobuf NO
-	-max_fanout 100000
-	-bufg 32
-	-register_duplication YES
-	-register_balancing No
-	-optimize_primitives NO
-	-use_clock_enable Auto
-	-use_sync_set Auto
-	-use_sync_reset Auto
-	-iob auto
-	-equivalent_register_removal YES
-	-slice_utilization_ratio_maxmargin 5
 EOT
 
 cat > $job.prj <<- EOT
 	verilog work "../../rtl/$job.v"
 EOT
 
-. /opt/Xilinx/14.2/ISE_DS/settings64.sh
+. /opt/Xilinx/14.5/ISE_DS/settings64.sh
 
 xst -ifn $job.xst
 netgen -w -ofmt verilog $job.ngc $job
diff --git a/tests/xsthammer/xl_cells.v b/tests/xsthammer/xl_cells.v
index 6a3fa7996..775c84d24 100644
--- a/tests/xsthammer/xl_cells.v
+++ b/tests/xsthammer/xl_cells.v
@@ -8,6 +8,14 @@ input I;
 output O = !I;
 endmodule
 
+module LUT1(O, I0);
+parameter INIT = 0;
+input I0;
+wire [1:0] lutdata = INIT;
+wire [0:0] idx = { I0 };
+output O = lutdata[idx];
+endmodule
+
 module LUT2(O, I0, I1);
 parameter INIT = 0;
 input I0, I1;
diff --git a/tests/xsthammer/xl_cells_tb.v b/tests/xsthammer/xl_cells_tb.v
index a7472e4f1..17e0a2798 100644
--- a/tests/xsthammer/xl_cells_tb.v
+++ b/tests/xsthammer/xl_cells_tb.v
@@ -14,6 +14,17 @@ XL_INV XL(.O(XL_O), .I(I));
 output ok = MY_O == XL_O;
 endmodule
 
+module TB_LUT1(ok, I0);
+input I0;
+wire [1:0] MY_O, XL_O;
+genvar i;
+generate for (i=0; i<2; i=i+1) begin:V
+	MY_LUT1 #(.INIT(i)) MY(.O(MY_O[i]), .I0(I0));
+	XL_LUT1 #(.INIT(i)) XL(.O(XL_O[i]), .I0(I0));
+end endgenerate
+output ok = MY_O == XL_O;
+endmodule
+
 module TB_LUT2(ok, I0, I1);
 input I0, I1;
 wire [3:0] MY_O, XL_O;
diff --git a/tests/xsthammer/xl_cells_tb.ys b/tests/xsthammer/xl_cells_tb.ys
index 616f1b278..536c64a15 100644
--- a/tests/xsthammer/xl_cells_tb.ys
+++ b/tests/xsthammer/xl_cells_tb.ys
@@ -6,6 +6,7 @@ read_verilog xl_cells_tb.v
 
 rename GND   MY_GND
 rename INV   MY_INV
+rename LUT1  MY_LUT1
 rename LUT2  MY_LUT2
 rename LUT3  MY_LUT3
 rename LUT4  MY_LUT4
@@ -16,20 +17,22 @@ rename MUXF7 MY_MUXF7
 rename VCC   MY_VCC
 rename XORCY MY_XORCY
 
-read_verilog /opt/Xilinx/14.2/ISE_DS/ISE/verilog/src/unisims/GND.v
-read_verilog /opt/Xilinx/14.2/ISE_DS/ISE/verilog/src/unisims/INV.v
-read_verilog /opt/Xilinx/14.2/ISE_DS/ISE/verilog/src/unisims/LUT2.v
-read_verilog /opt/Xilinx/14.2/ISE_DS/ISE/verilog/src/unisims/LUT3.v
-read_verilog /opt/Xilinx/14.2/ISE_DS/ISE/verilog/src/unisims/LUT4.v
-read_verilog /opt/Xilinx/14.2/ISE_DS/ISE/verilog/src/unisims/LUT5.v
-read_verilog /opt/Xilinx/14.2/ISE_DS/ISE/verilog/src/unisims/LUT6.v
-read_verilog /opt/Xilinx/14.2/ISE_DS/ISE/verilog/src/unisims/MUXCY.v
-read_verilog /opt/Xilinx/14.2/ISE_DS/ISE/verilog/src/unisims/MUXF7.v
-read_verilog /opt/Xilinx/14.2/ISE_DS/ISE/verilog/src/unisims/VCC.v
-read_verilog /opt/Xilinx/14.2/ISE_DS/ISE/verilog/src/unisims/XORCY.v
+read_verilog /opt/Xilinx/14.5/ISE_DS/ISE/verilog/src/unisims/GND.v
+read_verilog /opt/Xilinx/14.5/ISE_DS/ISE/verilog/src/unisims/INV.v
+read_verilog /opt/Xilinx/14.5/ISE_DS/ISE/verilog/src/unisims/LUT1.v
+read_verilog /opt/Xilinx/14.5/ISE_DS/ISE/verilog/src/unisims/LUT2.v
+read_verilog /opt/Xilinx/14.5/ISE_DS/ISE/verilog/src/unisims/LUT3.v
+read_verilog /opt/Xilinx/14.5/ISE_DS/ISE/verilog/src/unisims/LUT4.v
+read_verilog /opt/Xilinx/14.5/ISE_DS/ISE/verilog/src/unisims/LUT5.v
+read_verilog /opt/Xilinx/14.5/ISE_DS/ISE/verilog/src/unisims/LUT6.v
+read_verilog /opt/Xilinx/14.5/ISE_DS/ISE/verilog/src/unisims/MUXCY.v
+read_verilog /opt/Xilinx/14.5/ISE_DS/ISE/verilog/src/unisims/MUXF7.v
+read_verilog /opt/Xilinx/14.5/ISE_DS/ISE/verilog/src/unisims/VCC.v
+read_verilog /opt/Xilinx/14.5/ISE_DS/ISE/verilog/src/unisims/XORCY.v
 
 rename GND   XL_GND
 rename INV   XL_INV
+rename LUT1  XL_LUT1
 rename LUT2  XL_LUT2
 rename LUT3  XL_LUT3
 rename LUT4  XL_LUT4
@@ -47,6 +50,7 @@ opt_clean
 
 sat -verify -prove ok 1'b1 TB_GND
 sat -verify -prove ok 1'b1 TB_INV
+sat -verify -prove ok 1'b1 TB_LUT1
 sat -verify -prove ok 1'b1 TB_LUT2
 sat -verify -prove ok 1'b1 TB_LUT3
 sat -verify -prove ok 1'b1 TB_LUT4