diff --git a/src/CompilationDatabase.h b/src/CompilationDatabase.h
index 860f7bf..0527fdf 100644
--- a/src/CompilationDatabase.h
+++ b/src/CompilationDatabase.h
@@ -5,7 +5,6 @@
 #include <string>
 
 namespace clang {
-  class CompileCommands;
   class CompilationDatabase {
   public:
     explicit CompilationDatabase(const std::string &project_path);
diff --git a/src/CompileCommand.cc b/src/CompileCommand.cc
index 4ba97b7..3d98579 100644
--- a/src/CompileCommand.cc
+++ b/src/CompileCommand.cc
@@ -1,11 +1,6 @@
 #include "CompileCommand.h"
 #include "CompileCommands.h"
 
-clang::CompileCommand::
-CompileCommand(int nth, clang::CompileCommands &commands) {
-  cx_command = clang_CompileCommands_getCommand(commands.cx_commands, nth);
-}
-
 std::string clang::CompileCommand::
 get_command() {
   std::string res;
diff --git a/src/CompileCommand.h b/src/CompileCommand.h
index 51f64a3..ba87d7d 100644
--- a/src/CompileCommand.h
+++ b/src/CompileCommand.h
@@ -1,12 +1,12 @@
 #ifndef COMPILECOMMAND_H_
 #define COMPILECOMMAND_H_
-#include "CompilationDatabase.h"
+#include <clang-c/CXCompilationDatabase.h>
 #include <vector>
 
 namespace clang {
   class CompileCommand {
   public:
-    CompileCommand(int nth, CompileCommands &commands);
+    CompileCommand(const CXCompileCommand& cx_command) : cx_command(cx_command) {};
     std::string get_command();
     std::vector<std::string> get_command_as_args();
 
diff --git a/src/CompileCommands.cc b/src/CompileCommands.cc
index 26ea944..2b5494b 100644
--- a/src/CompileCommands.cc
+++ b/src/CompileCommands.cc
@@ -18,7 +18,7 @@ get_commands() {
   unsigned N = clang_CompileCommands_getSize(cx_commands);
   std::vector<clang::CompileCommand> res;
   for (unsigned i = 0; i < N; i++) {
-    res.emplace_back(clang::CompileCommand(i, *this));
+    res.emplace_back(clang_CompileCommands_getCommand(cx_commands, i));
   }
   return res;
 }
diff --git a/src/Cursor.h b/src/Cursor.h
index 05824d9..4b5fc10 100644
--- a/src/Cursor.h
+++ b/src/Cursor.h
@@ -175,7 +175,7 @@ namespace clang {
 
   class Cursor {
   public:
-    Cursor(CXCursor cx_cursor) : cx_cursor(cx_cursor) {}
+    Cursor(const CXCursor &cx_cursor) : cx_cursor(cx_cursor) {}
     Cursor(CXTranslationUnit &cx_tu, SourceLocation &source_location);
     const CursorKind get_kind();
     SourceLocation get_source_location() const;
diff --git a/src/SourceLocation.h b/src/SourceLocation.h
index ad25c24..0837dc1 100644
--- a/src/SourceLocation.h
+++ b/src/SourceLocation.h
@@ -7,7 +7,7 @@ namespace clang {
   
   class SourceLocation {
   public:
-    SourceLocation(CXSourceLocation cx_location) : cx_location(cx_location) {}
+    SourceLocation(const CXSourceLocation& cx_location) : cx_location(cx_location) {}
     
     SourceLocation(CXTranslationUnit &cx_tu,
                    const std::string &filename,
diff --git a/src/SourceRange.h b/src/SourceRange.h
index 6ca89a3..7a85504 100644
--- a/src/SourceRange.h
+++ b/src/SourceRange.h
@@ -13,7 +13,7 @@ namespace clang {
   
   class SourceRange {
   public:
-    SourceRange(CXSourceRange cx_range) : cx_range(cx_range) {}
+    SourceRange(const CXSourceRange& cx_range) : cx_range(cx_range) {}
     SourceRange(SourceLocation &start, SourceLocation &end);
     std::pair<SourceLocation, SourceLocation> get_source_locations();
     static RangeData get_range_data(SourceLocation &start, SourceLocation &end);