diff --git a/sim/atomsim.cpp b/sim/atomsim.cpp
index 0e1030d0..aa6a1e5a 100755
--- a/sim/atomsim.cpp
+++ b/sim/atomsim.cpp
@@ -11,7 +11,7 @@ Atomsim::Atomsim(Atomsim_config sim_config, Backend_config bk_config):
     backend_(this, bk_config)  // create backend
 {   
     // get input file disassembly   
-    disassembly_ = getDisassembly(sim_config_.ifile);
+    getDisassembly(&disassembly_, sim_config_.ifile);
 
     // clear breakpoints
     for(int i=0; i<NUM_MAX_BREAKPOINTS; i++) {
diff --git a/sim/util.cpp b/sim/util.cpp
index 60da03a2..65c8f467 100755
--- a/sim/util.cpp
+++ b/sim/util.cpp
@@ -209,7 +209,7 @@ std::string GetStdoutFromCommand(std::string cmd, bool get_output = true) {
 }
 
 
-std::map<uint32_t, DisassembledLine> getDisassembly(std::string filename)
+void getDisassembly(std::map<uint32_t, DisassembledLine> *dis, std::string filename)
 {
 	std::string command = "";
 	#ifdef RV32_COMPILER
@@ -223,9 +223,6 @@ std::map<uint32_t, DisassembledLine> getDisassembly(std::string filename)
 	std::string output = GetStdoutFromCommand(command);
 	
 	std::stringstream s(output);
-
-	// Parse command output
-	std::map<uint32_t, DisassembledLine> dis;
 	
 	std::string line;
     bool in_disassembly = false;
@@ -274,12 +271,15 @@ std::map<uint32_t, DisassembledLine> getDisassembly(std::string filename)
                 .instr = instrn,
                 .disassembly = dism
             };
-            dis.insert({addr, dl});   
+
+            // insert if not already present
+            if(dis->count(addr) == 0) {
+                dis->insert({addr, dl});
+            }
         }
         else {
             // Parse the rest
             // printf("Unk[%s]\n", line.c_str());
         }
     }
-	return dis;
 }
\ No newline at end of file
diff --git a/sim/util.hpp b/sim/util.hpp
index 1c567e27..ef75b692 100755
--- a/sim/util.hpp
+++ b/sim/util.hpp
@@ -176,7 +176,7 @@ struct DisassembledLine
 /**
  * @brief Get the Disassembly of input file using riscv objdump
  * 
+ * @param dis std::map<uint32_t, std::string> map of disassembly
  * @param filename input filename
- * @return std::map<uint32_t, std::string> map of disassembly
  */
-std::map<uint32_t, DisassembledLine> getDisassembly(std::string filename);
\ No newline at end of file
+void getDisassembly(std::map<uint32_t, DisassembledLine> *dis, std::string filename);
\ No newline at end of file