diff --git a/mythril/support/truffle.py b/mythril/support/truffle.py
index e1857f05..e37b2a50 100644
--- a/mythril/support/truffle.py
+++ b/mythril/support/truffle.py
@@ -1,5 +1,6 @@
 import os
 import re
+import sys
 import json
 from mythril.ether import util
 from mythril.ether.ethcontract import ETHContract
@@ -14,67 +15,73 @@ def analyze_truffle_project():
     
     build_dir = os.path.join(project_root, "build", "contracts")
 
-    contract_files = os.listdir(build_dir)
+    files = os.listdir(build_dir)
 
-    for contract_file in contract_files:
+    for filename in files:
 
-        with open(os.path.join(build_dir, contract_file)) as cf:
-            contractdata = json.load(cf)
+        if re.match(r'.*\.json$', filename):
 
-        name = contractdata['contractName']
-        bytecode = contractdata['deployedBytecode']
+            with open(os.path.join(build_dir, filename)) as cf:
+                contractdata = json.load(cf)
 
-        if (len(bytecode) < 4):
-            continue
+            try:
+                name = contractdata['contractName']
+                bytecode = contractdata['deployedBytecode']
+            except:
+                print("Unable to parse contract data. Please use Truffle 4 to compile your project.")
+                sys.exit()
 
-        ethcontract= ETHContract(bytecode, name=name, address = util.get_indexed_address(0))
 
-        contracts = [ethcontract]
+            if (len(bytecode) < 4):
+                continue
 
-        states = StateSpace(contracts, max_depth = 10)
-        report = fire_lasers(states)
+            ethcontract= ETHContract(bytecode, name=name, address = util.get_indexed_address(0))
 
-        # augment with source code
+            contracts = [ethcontract]
 
-        disassembly = ethcontract.get_disassembly()
-        source = contractdata['source']
+            states = StateSpace(contracts, max_depth = 10)
+            report = fire_lasers(states)
 
-        deployedSourceMap = contractdata['deployedSourceMap'].split(";")
+            # augment with source code
 
-        mappings = []
-        i = 0
+            disassembly = ethcontract.get_disassembly()
+            source = contractdata['source']
 
-        while(i < len(deployedSourceMap)):
+            deployedSourceMap = contractdata['deployedSourceMap'].split(";")
 
-            m = re.search(r"^(\d+):*(\d+)", deployedSourceMap[i])
+            mappings = []
+            i = 0
 
-            if (m):
-                offset = m.group(1)
-                length = m.group(2)
-            else:
-                m = re.search(r"^:(\d+)", deployedSourceMap[i])
+            while(i < len(deployedSourceMap)):
+
+                m = re.search(r"^(\d+):*(\d+)", deployedSourceMap[i])
 
-                if m:
-                    length = m.group(1)
+                if (m):
+                    offset = m.group(1)
+                    length = m.group(2)
+                else:
+                    m = re.search(r"^:(\d+)", deployedSourceMap[i])
 
-            mappings.append((int(offset), int(length)))
+                    if m:
+                        length = m.group(1)
 
-            i += 1
+                mappings.append((int(offset), int(length)))
 
-        for key, issue in report.issues.items():
+                i += 1
 
-            index = helper.get_instruction_index(disassembly.instruction_list, issue.pc)
+            for key, issue in report.issues.items():
 
-            if index:
-                issue.code_start = mappings[index][0]
-                issue.code_length = mappings[index][1]
-                issue.code = source[mappings[index][0]: mappings[index][0] + mappings[index][1]]
+                index = helper.get_instruction_index(disassembly.instruction_list, issue.pc)
 
-        
+                if index:
+                    issue.code_start = mappings[index][0]
+                    issue.code_length = mappings[index][1]
+                    issue.code = source[mappings[index][0]: mappings[index][0] + mappings[index][1]]
 
-        if len(report.issues):
-            print("Analysis result for " + name + ":\n" + report.as_text())
-        else:
-            print("Analysis result for " + name + ": No issues found.") 
+
+            if len(report.issues):
+                print("Analysis result for " + name + ":\n" + report.as_text())
+            else:
+                print("Analysis result for " + name + ": No issues found.")