diff --git a/CMakeLists.txt b/CMakeLists.txt
index 4ef9a7b..d343e5a 100644
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -10,6 +10,9 @@ target_compile_options(common_options INTERFACE
   -Wall
   -Wextra
 )
+target_include_directories(common_options INTERFACE
+  src
+)
 
 add_subdirectory(src)
 add_subdirectory(tests)
diff --git a/src/abacus.cc b/src/abacus.cc
index 3e735a0..45d2394 100644
--- a/src/abacus.cc
+++ b/src/abacus.cc
@@ -1,4 +1,4 @@
-#include "parser-driver.hh" // FIXME: I would like `parse/parser-driver.hh` path instead...
+#include "parse/parser-driver.hh"
 
 int main() {
     abacus::parse::ParserDriver driver{};
diff --git a/src/bignum/CMakeLists.txt b/src/bignum/CMakeLists.txt
index b2434b7..6b64eb6 100644
--- a/src/bignum/CMakeLists.txt
+++ b/src/bignum/CMakeLists.txt
@@ -3,7 +3,3 @@ add_library(bignum STATIC
   bignum.hh
 )
 target_link_libraries(bignum PRIVATE common_options)
-
-target_include_directories(bignum PUBLIC
-  $<BUILD_INTERFACE:${CMAKE_CURRENT_SOURCE_DIR}>
-)
diff --git a/src/parse/CMakeLists.txt b/src/parse/CMakeLists.txt
index 3c87a92..22a706c 100644
--- a/src/parse/CMakeLists.txt
+++ b/src/parse/CMakeLists.txt
@@ -18,6 +18,6 @@ target_link_libraries(parse PRIVATE
 )
 
 target_include_directories(parse PUBLIC
-  $<BUILD_INTERFACE:${CMAKE_CURRENT_SOURCE_DIR}>
   $<BUILD_INTERFACE:${CMAKE_CURRENT_BINARY_DIR}>
+  $<BUILD_INTERFACE:${CMAKE_CURRENT_SOURCE_DIR}>
 )
diff --git a/src/parse/parser-driver.hh b/src/parse/parser-driver.hh
index d5ba7ea..ad88efd 100644
--- a/src/parse/parser-driver.hh
+++ b/src/parse/parser-driver.hh
@@ -4,7 +4,7 @@
 
 #include "parser.hh"
 
-#include "bignum.hh" // FIXME: I would like `bignum/bignum.hh` path instead...
+#include "bignum/bignum.hh"
 
 namespace abacus::parse {
 
diff --git a/src/parse/parser.yy b/src/parse/parser.yy
index d8fbc87..07e3e3a 100644
--- a/src/parse/parser.yy
+++ b/src/parse/parser.yy
@@ -36,7 +36,7 @@ namespace abacus::parse {
 class ParserDriver;
 } // namespace abacus::parse
 
-#include "bignum.hh" // FIXME: I would like `bignum/bignum.hh` path instead...
+#include "bignum/bignum.hh"
 }
 
 %code provides {
diff --git a/tests/unit/bignum.cc b/tests/unit/bignum.cc
index f584778..b7306f4 100644
--- a/tests/unit/bignum.cc
+++ b/tests/unit/bignum.cc
@@ -2,7 +2,7 @@
 
 #include <gtest/gtest.h>
 
-#include "bignum.hh"
+#include "bignum/bignum.hh"
 
 using namespace abacus::bignum;