diff --git a/parse_misc.h b/parse_misc.h
index 46a937042..3d1f64754 100644
--- a/parse_misc.h
+++ b/parse_misc.h
@@ -30,10 +30,10 @@
  * YYLTYPE compels the lexor to use this type and not something other.
  */
 struct vlltype {
-      unsigned first_line;
-      unsigned first_column;
-      unsigned last_line;
-      unsigned last_column;
+      int first_line;
+      int first_column;
+      int last_line;
+      int last_column;
       const char*text;
       std::string get_fileline() const;
 };
diff --git a/vpi/vcd_priv2.cc b/vpi/vcd_priv2.cc
index fb01ce5a8..a41c5b5a4 100644
--- a/vpi/vcd_priv2.cc
+++ b/vpi/vcd_priv2.cc
@@ -230,7 +230,7 @@ extern "C" void vcd_work_sync(void)
       }
 }
 
-extern "C" extern "C" void vcd_work_flush(void)
+extern "C" void vcd_work_flush(void)
 {
       struct vcd_work_item_s*cell = grab_item();
       cell->type = WT_FLUSH;
diff --git a/vvp/config.h.in b/vvp/config.h.in
index edeeabf8e..0adfd2ae4 100644
--- a/vvp/config.h.in
+++ b/vvp/config.h.in
@@ -96,7 +96,7 @@ typedef uint64_t vvp_time64_t;
 # define TIME_FMT_X PRIx64
 #endif
 
-# if UINT64_T_AND_ULONG_SAME
+# ifdef UINT64_T_AND_ULONG_SAME
 #  define UL_AND_TIME64_SAME
 # endif