diff --git a/src/experiments/l4-sys/aluinstr.cc b/src/experiments/l4-sys/aluinstr.cc
index 37e83326..5bdeddd5 100644
--- a/src/experiments/l4-sys/aluinstr.cc
+++ b/src/experiments/l4-sys/aluinstr.cc
@@ -92,14 +92,14 @@ bool BochsALUInstructions::isALUInstruction(bxInstruction_c const *src) {
 	return false;
 }
 
-int BochsALUInstructions::randomEquivalent(bxInstruction_c &result,
+void BochsALUInstructions::randomEquivalent(bxInstruction_c &result,
                                                   std::string &details) const {
 	// find a random member of the same equivalence class
 	X86AluClass equClassID = lastInstr.aluClass;
 	if (equClassID == ALU_UNDEF) {
 		// something went wrong - just return the original instruction
 		result = lastOrigInstr;
-		return 10;
+		return;
 	}
 
 	InstrList const &destList = equivalenceClasses.at(equClassID);
@@ -136,13 +136,6 @@ int BochsALUInstructions::randomEquivalent(bxInstruction_c &result,
 	if (dest.opcodeRegisterOffset < BochsALUInstr::REG_COUNT) {
 		result.setRm(dest.opcodeRegisterOffset);
 	}
-
-	if (memcmp(&result, &lastOrigInstr, sizeof(bxInstruction_c)) == 0) {
-		fprintf(stderr,"randomEquivalent failed\n");
-		scanf("%*s");
-	}
-
-	return 0;
 }
 
 #ifdef DEBUG
diff --git a/src/experiments/l4-sys/aluinstr.hpp b/src/experiments/l4-sys/aluinstr.hpp
index 09af8bde..fb89f572 100644
--- a/src/experiments/l4-sys/aluinstr.hpp
+++ b/src/experiments/l4-sys/aluinstr.hpp
@@ -343,7 +343,7 @@ public:
 	 * @param result the resulting bxInstruction_c object as described above
 	 * @param details after completion contains details about \c result
 	 */
-	int randomEquivalent(bxInstruction_c &result, std::string &details) const;
+	void randomEquivalent(bxInstruction_c &result, std::string &details) const;
 protected:
 	/**
 	 * Convert a bxInstruction_c object into its matching BochsALUInstr object.
diff --git a/src/experiments/l4-sys/experiment.cc b/src/experiments/l4-sys/experiment.cc
index b5fd32b3..e3b4c57d 100644
--- a/src/experiments/l4-sys/experiment.cc
+++ b/src/experiments/l4-sys/experiment.cc
@@ -600,7 +600,7 @@ bool L4SysExperiment::run() {
 		// now exchange it with a random equivalent
 		bxInstruction_c newInstr;
 		string details;
-		int result = aluInstrObject.randomEquivalent(newInstr, details);
+		aluInstrObject.randomEquivalent(newInstr, details);
 		if (memcmp(&newInstr, currInstr, sizeof(bxInstruction_c)) == 0) {
 			// something went wrong - exit experiment
 			param.msg.set_resulttype(param.msg.UNKNOWN);