diff --git a/tests/simple/run-test.sh b/tests/simple/run-test.sh
index 967ac49f2..f20fd0d30 100755
--- a/tests/simple/run-test.sh
+++ b/tests/simple/run-test.sh
@@ -12,7 +12,7 @@ done
 shift "$((OPTIND-1))"
 
 # check for Icarus Verilog
-if ! which iverilog > /dev/null ; then
+if ! command -v iverilog > /dev/null ; then
   echo "$0: Error: Icarus Verilog 'iverilog' not found."
   exit 1
 fi
diff --git a/tests/simple_abc9/run-test.sh b/tests/simple_abc9/run-test.sh
index 8df6994e3..0d4262005 100755
--- a/tests/simple_abc9/run-test.sh
+++ b/tests/simple_abc9/run-test.sh
@@ -12,7 +12,7 @@ done
 shift "$((OPTIND-1))"
 
 # check for Icarus Verilog
-if ! which iverilog > /dev/null ; then
+if ! command -v iverilog > /dev/null ; then
   echo "$0: Error: Icarus Verilog 'iverilog' not found."
   exit 1
 fi