diff --git a/bin/wsim b/bin/wsim
index 3f6cbaaae..ca44e22a6 100755
--- a/bin/wsim
+++ b/bin/wsim
@@ -59,12 +59,12 @@ if(args.testsuite.endswith('.elf') and args.elf == ""): # No --elf argument; che
                 args.testsuite = fields[1] + "_" + fields[3]
             else:
                 args.testsuite = fields[2] + "_" + fields[3]
-        elif ('/' in args.testsuite): 
+        elif ('/' in args.testsuite):
             args.testsuite=args.testsuite.rsplit('/', 1)[1] # strip off path if present
     else:
         print("ELF file not found: " + args.testsuite)
         exit(1)
-    
+
 if(args.lockstep and not args.testsuite.endswith('.elf')):
     print(f"Invalid Options. Cannot run a testsuite, {args.testsuite} with lockstep. Must run a single elf.")
     exit(1)
@@ -89,13 +89,14 @@ if(int(args.locksteplog) >= 1): EnableLog = 1
 else: EnableLog = 0
 prefix = ""
 if (args.lockstep or args.lockstepverbose or args.fcov or args.fcovimp):
-   if (args.sim == "questa" or args.sim == "vcs"):
+    if (args.sim == "questa" or args.sim == "vcs"):
         prefix = "IMPERAS_TOOLS=" + WALLY + "/config/"+args.config+"/imperas.ic"
-   if (args.sim == "questa"):
-        prefix = "MTI_VCO_MODE=64 " + prefix
+# Force Questa to use 64-bit mode, sometimes it defaults to 32-bit even on 64-bit machines
+if (args.sim == "questa"):
+    prefix = "MTI_VCO_MODE=64 " + prefix
 
 if (args.lockstep or args.lockstepverbose):
-    if(args.locksteplog != 0): ImperasPlusArgs = " +IDV_TRACE2LOG=" + str(EnableLog) + " +IDV_TRACE2LOG_AFTER=" + str(args.locksteplog) 
+    if(args.locksteplog != 0): ImperasPlusArgs = " +IDV_TRACE2LOG=" + str(EnableLog) + " +IDV_TRACE2LOG_AFTER=" + str(args.locksteplog)
     else: ImperasPlusArgs = ""
     if(args.fcovimp):
         CovEnableStr = "1" if int(args.covlog) > 0  else "0"