diff --git a/cad/iverilog/files/patch-driver_cflexor.lex b/cad/iverilog/files/patch-driver_cflexor.lex
new file mode 100644
index 000000000000..361a476f8bd8
--- /dev/null
+++ b/cad/iverilog/files/patch-driver_cflexor.lex
@@ -0,0 +1,10 @@
+--- driver/cflexor.lex.orig	2020-08-18 17:06:30 UTC
++++ driver/cflexor.lex
+@@ -30,6 +30,7 @@
+ static int comment_enter;
+ static char* trim_trailing_white(char*txt, int trim);
+ 
++char *current_file;
+ /*
+  * Mostly copied from the flex manual. Do not make this arbitrary
+  * depth without checking for looping files.
diff --git a/cad/iverilog/files/patch-driver_cfparse__misc.h b/cad/iverilog/files/patch-driver_cfparse__misc.h
new file mode 100644
index 000000000000..640ecb5751a4
--- /dev/null
+++ b/cad/iverilog/files/patch-driver_cfparse__misc.h
@@ -0,0 +1,10 @@
+--- driver/cfparse_misc.h.orig	2020-08-18 17:06:43 UTC
++++ driver/cfparse_misc.h
+@@ -39,6 +39,6 @@ int cferror(const char *);
+ int cfparse(void);
+ void switch_to_command_file(const char *);
+ void destroy_lexor(void);
+-char *current_file;
++extern char *current_file;
+ 
+ #endif /* IVL_cfparse_misc_H */
diff --git a/cad/iverilog/files/patch-libveriuser_priv.h b/cad/iverilog/files/patch-libveriuser_priv.h
new file mode 100644
index 000000000000..abae6a6e3fb4
--- /dev/null
+++ b/cad/iverilog/files/patch-libveriuser_priv.h
@@ -0,0 +1,12 @@
+--- libveriuser/priv.h.orig	2020-08-18 15:47:00 UTC
++++ libveriuser/priv.h
+@@ -30,7 +30,8 @@ extern char* __acc_newstring(const char*txt);
+ 
+ /*
+  * Trace file for logging ACC and TF calls.
++ * Defined in libveriuser/priv.c
+  */
+-FILE* pli_trace;
++extern FILE* pli_trace;
+ 
+ #endif /* IVL_priv_H */