diff --git a/CMakeLists.txt b/CMakeLists.txt
index b362caa..61a275b 100644
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -45,6 +45,7 @@ add_executable(sample_parser
   ${FLEX_verilog_lexer_OUTPUTS}
   ${BISON_verilog_parser_OUTPUTS}
 )
+target_include_directories(sample_parser SYSTEM PRIVATE ${FLEX_INCLUDE_DIRS})
 
 # A drop-in replacement OpenTimer Verilog parser
 add_executable(ot_parser
@@ -52,6 +53,7 @@ add_executable(ot_parser
   ${FLEX_verilog_lexer_OUTPUTS}
   ${BISON_verilog_parser_OUTPUTS}
 )
+target_include_directories(ot_parser SYSTEM PRIVATE ${FLEX_INCLUDE_DIRS})
 
 
 
@@ -67,5 +69,6 @@ set(VP_UTEST_DIR ${PROJECT_SOURCE_DIR}/unittest)
 set(CMAKE_RUNTIME_OUTPUT_DIRECTORY ${VP_UTEST_DIR})
 
 add_executable(regression unittest/regression.cpp ${FLEX_verilog_lexer_OUTPUTS} ${BISON_verilog_parser_OUTPUTS})
+target_include_directories(regression SYSTEM PRIVATE ${FLEX_INCLUDE_DIRS})
 add_test(regression ${VP_UTEST_DIR}/regression)
 
diff --git a/parser-verilog/verilog_data.hpp b/parser-verilog/verilog_data.hpp
index 59366e6..c4350ee 100644
--- a/parser-verilog/verilog_data.hpp
+++ b/parser-verilog/verilog_data.hpp
@@ -6,7 +6,7 @@
 #include <fstream>
 #include <iostream>
 #include <variant>
-#include <experimental/filesystem>
+#include <vector>
 
 
 namespace verilog {
diff --git a/parser-verilog/verilog_lexer.l b/parser-verilog/verilog_lexer.l
index ce7f194..9880c71 100644
--- a/parser-verilog/verilog_lexer.l
+++ b/parser-verilog/verilog_lexer.l
@@ -1,3 +1,8 @@
+/* Avoid redefinition warnings on MSVC */
+%top{
+#include <stdint.h>
+}
+
 %{
 /* C++ string header, for string ops below */
 #include <string>