diff --git a/src/core/util/llvmdisassembler/LLVMtoFailTranslator.cpp b/src/core/util/llvmdisassembler/LLVMtoFailTranslator.cpp
index 0d10e1a2..f99f0070 100644
--- a/src/core/util/llvmdisassembler/LLVMtoFailTranslator.cpp
+++ b/src/core/util/llvmdisassembler/LLVMtoFailTranslator.cpp
@@ -9,7 +9,7 @@ const LLVMtoFailTranslator::reginfo_t &	 LLVMtoFailTranslator::getFailRegisterID
 	if( it != llvm_to_fail_map.end() ) {// found
 		return (*it).second;
 	} else { // not found
-		std::cout << "Fail ID for LLVM Register id " << regid << " not found :(" << std::endl;
+		std::cout << "Fail ID for LLVM Register id " << std::dec << regid << " not found :(" << std::endl;
 		//exit(EXIT_FAILURE);
 		return notfound;
 	}
diff --git a/src/core/util/llvmdisassembler/LLVMtoFailTranslator.hpp b/src/core/util/llvmdisassembler/LLVMtoFailTranslator.hpp
index 5849e12c..f64cf07a 100644
--- a/src/core/util/llvmdisassembler/LLVMtoFailTranslator.hpp
+++ b/src/core/util/llvmdisassembler/LLVMtoFailTranslator.hpp
@@ -51,6 +51,12 @@ protected:
 
 
 public:
+	/**
+	 * Translates a backend-specific register ID to a Fail register ID.
+	 * @param regid A backend-specific register ID.
+	 * @return A Fail* register ID, or LLVMtoFailTranslator::notfound if no
+	 *         mapping was found.
+	 */
 	const reginfo_t &  getFailRegisterID(unsigned int regid);
 
 	regdata_t getRegisterContent(ConcreteCPU & cpu, const reginfo_t & reg);
@@ -63,7 +69,7 @@ public:
 	}
 
 	int getFailRegisterId(unsigned int regid) { return this->getFailRegisterID(regid).id; };
-private:
+
 	reginfo_t notfound;
 };
 
diff --git a/tools/import-trace/RegisterImporter.cc b/tools/import-trace/RegisterImporter.cc
index 5564a184..4d6605d6 100644
--- a/tools/import-trace/RegisterImporter.cc
+++ b/tools/import-trace/RegisterImporter.cc
@@ -130,6 +130,12 @@ bool RegisterImporter::handle_ip_event(fail::simtime_t curtime, instruction_coun
 	for (std::vector<LLVMDisassembler::register_t>::const_iterator it = opcode.reg_uses.begin();
 		 it != opcode.reg_uses.end(); ++it) {
 		const LLVMtoFailTranslator::reginfo_t &info = ltof.getFailRegisterID(*it);
+		if (&info == &ltof.notfound) {
+			LOG << "Could not find a mapping for LLVM input register #" << std::dec << *it
+			    << " at IP " << std::hex << ev.ip()
+			    << ", skipping" << std::endl;
+			continue;
+		}
 
 		/* if not tracing flags, but flags register -> ignore it
 		   if not tracing gp, but ! flags -> ignore it*/
@@ -146,6 +152,13 @@ bool RegisterImporter::handle_ip_event(fail::simtime_t curtime, instruction_coun
 	for (std::vector<LLVMDisassembler::register_t>::const_iterator it = opcode.reg_defs.begin();
 		 it != opcode.reg_defs.end(); ++it) {
 		const LLVMtoFailTranslator::reginfo_t &info = ltof.getFailRegisterID(*it);
+		if (&info == &ltof.notfound) {
+			LOG << "Could not find a mapping for LLVM output register #" << std::dec << *it
+			    << " at IP " << std::hex << ev.ip()
+			    << ", skipping" << std::endl;
+			continue;
+		}
+
 		/* if not tracing flags, but flags register -> ignore it
 		   if not tracing gp, but ! flags -> ignore it*/
 		if (info.id == RID_FLAGS && !do_flags)