diff --git a/aegisub/libaegisub/common/charset.cpp b/aegisub/libaegisub/common/charset.cpp
index 9a5fefbea..3e1e961f0 100644
--- a/aegisub/libaegisub/common/charset.cpp
+++ b/aegisub/libaegisub/common/charset.cpp
@@ -18,14 +18,12 @@
 /// @brief Character set detection and manipulation utilities.
 /// @ingroup libaegisub
 
-
-#include "libaegisub/charset.h"
 #include "charset_ucd.h"
 
 namespace agi {
 	namespace charset {
 
-const std::string Detect(const std::string file) {
+std::string Detect(const std::string &file) {
 	UCDetect ucd(file);
 	return ucd.Single();
 }
diff --git a/aegisub/libaegisub/common/charset_ucd.cpp b/aegisub/libaegisub/common/charset_ucd.cpp
index 5bb1f91e6..b46a5c75f 100644
--- a/aegisub/libaegisub/common/charset_ucd.cpp
+++ b/aegisub/libaegisub/common/charset_ucd.cpp
@@ -18,23 +18,18 @@
 /// @brief Character set detection using Universalchardet
 /// @ingroup libaegisub
 
+#include "charset_ucd.h"
 
 #ifndef LAGI_PRE
-#include <fstream>
-#include <string>
-#include <map>
-
 #include "../../universalchardet/nsCharSetProber.h"
 #endif
 
-#include "libaegisub/charset.h"
-#include "charset_ucd.h"
 #include "libaegisub/io.h"
 
 namespace agi {
 	namespace charset {
 
-UCDetect::UCDetect(const std::string file): nsUniversalDetector(NS_FILTER_ALL) {
+UCDetect::UCDetect(const std::string &file): nsUniversalDetector(NS_FILTER_ALL) {
 	{
 		std::ifstream *fp;
 		fp = io::Open(file);
diff --git a/aegisub/libaegisub/common/charset_ucd.h b/aegisub/libaegisub/common/charset_ucd.h
index b21e43c2b..a9d59323b 100644
--- a/aegisub/libaegisub/common/charset_ucd.h
+++ b/aegisub/libaegisub/common/charset_ucd.h
@@ -18,15 +18,21 @@
 /// @brief Character set detection using Universalchardet
 /// @ingroup libaegisub
 
+#include "libaegisub/charset.h"
+
 #ifndef LAGI_PRE
+#include <string>
+
 #ifndef _WIN32
 #define _X86_ 1
 #endif
+
 #include "../../universalchardet/nscore.h"
 #include "../../universalchardet/nsUniversalDetector.h"
 #include "../../universalchardet/nsMBCSGroupProber.h"
 #endif
 
+
 namespace agi {
 	namespace charset {
 
@@ -45,7 +51,7 @@ public:
 
 	/// @brief Detect character set of a file using UniversalCharDetect
 	/// @param file File to check
-	UCDetect(const std::string file);
+	UCDetect(const std::string &file);
 
 	/// @brief Detect character set of a file using UniversalCharDet
 	/// @param out[out] Map to load list into ordered by confidence
diff --git a/aegisub/libaegisub/include/libaegisub/charset.h b/aegisub/libaegisub/include/libaegisub/charset.h
index 71c9cb169..fca82fa68 100644
--- a/aegisub/libaegisub/include/libaegisub/charset.h
+++ b/aegisub/libaegisub/include/libaegisub/charset.h
@@ -19,8 +19,11 @@
 /// @ingroup libaegisub
 
 #ifndef LAGI_PRE
-#endif
+#include <fstream>
+#include <functional>
 #include <map>
+#include <string>
+#endif
 #include <libaegisub/exception.h>
 
 namespace agi {
@@ -34,13 +37,13 @@ typedef std::map<float, std::string, std::greater_equal<float> > CharsetListDete
 
 /// @brief Return a complete list of detected character sets ordered by precidence.
 /// @param file File to check
-/// @param[in] list Map to load detected list into.
+/// @param[out] list Map to load detected list into.
 void DetectAll(const std::string file, CharsetListDetected &list);
 
 /// @brief Returns the character set with the highest confidence
 /// @param file File to check
 /// @return Detected character set.
-const std::string Detect(const std::string file);
+std::string Detect(const std::string &file);
 
 
 	} // namespace util
diff --git a/aegisub/libaegisub/include/libaegisub/io.h b/aegisub/libaegisub/include/libaegisub/io.h
index f23548e10..399164ee2 100644
--- a/aegisub/libaegisub/include/libaegisub/io.h
+++ b/aegisub/libaegisub/include/libaegisub/io.h
@@ -19,6 +19,8 @@
 /// @ingroup libaegisub
 
 #ifndef LAGI_PRE
+#include <string>
+#include <fstream>
 #endif
 
 #include <libaegisub/exception.h>
diff --git a/aegisub/libaegisub/include/libaegisub/types.h b/aegisub/libaegisub/include/libaegisub/types.h
index 909eea76e..ba5fbeecc 100644
--- a/aegisub/libaegisub/include/libaegisub/types.h
+++ b/aegisub/libaegisub/include/libaegisub/types.h
@@ -20,6 +20,8 @@
 
 #ifndef LAGI_PRE
 
+#include "config.h"
+
 #ifdef HAVE_SYS_TIME_H
 #  include <sys/time.h>
 #else