diff --git a/ispc.cpp b/ispc.cpp
index 046c64c4..1a99154b 100644
--- a/ispc.cpp
+++ b/ispc.cpp
@@ -448,7 +448,7 @@ Target::Target(const char *arch, const char *cpu, const char *isa, bool pic) :
     }
     else if (!strcasecmp(isa, "avx-i64x4") ) {
         this->m_isa = Target::AVX;
-        this->m_nativeVectorWidth = 4;
+        this->m_nativeVectorWidth = 8;  /* native vector width in terms of floats */
         this->m_vectorWidth = 4;
         this->m_attributes = "+avx,+popcnt,+cmov";
         this->m_maskingIsFree = false;
diff --git a/run_tests.py b/run_tests.py
index 180205a0..9729930f 100755
--- a/run_tests.py
+++ b/run_tests.py
@@ -75,7 +75,7 @@ if not os.path.exists(ispc_exe):
     sys.stderr.write("Fatal error: missing ispc compiler: %s\n" % ispc_exe)
     sys.exit()
 
-ispc_exe += " -g " + options.ispc_flags
+ispc_exe += " " + options.ispc_flags
 
 if __name__ == '__main__':
     sys.stdout.write("ispc compiler: %s\n" % ispc_exe)