diff --git a/crypto/func/func.cpp b/crypto/func/func.cpp
index 43bba4ea..b260c885 100644
--- a/crypto/func/func.cpp
+++ b/crypto/func/func.cpp
@@ -178,6 +178,18 @@ void usage(const char* progname) {
   std::exit(2);
 }
 
+void output_inclusion_stack() {
+  while (!funC::inclusion_locations.empty()) {
+    src::SrcLocation loc = funC::inclusion_locations.top();
+    funC::inclusion_locations.pop();
+    if (loc.fdescr) {
+      std::cerr << "note: included from ";
+      loc.show(std::cerr);
+      std::cerr << std::endl;
+    }
+  }
+}
+
 std::string output_filename;
 
 int main(int argc, char* const argv[]) {
@@ -241,7 +253,7 @@ int main(int argc, char* const argv[]) {
   int ok = 0, proc = 0;
   try {
     while (optind < argc) {
-      funC::generated_from += std::string{"`"} + argv[optind] + "` ";
+      // funC::generated_from += std::string{"`"} + argv[optind] + "` ";
       ok += funC::parse_source_file(argv[optind++]);
       proc++;
     }
@@ -268,14 +280,17 @@ int main(int argc, char* const argv[]) {
     funC::generate_output();
   } catch (src::Fatal& fatal) {
     std::cerr << "fatal: " << fatal << std::endl;
+    output_inclusion_stack();
     std::exit(1);
   } catch (src::Error& error) {
     std::cerr << error << std::endl;
+    output_inclusion_stack();
     std::exit(1);
   } catch (funC::UnifyError& unif_err) {
     std::cerr << "fatal: ";
     unif_err.print_message(std::cerr);
     std::cerr << std::endl;
+    output_inclusion_stack();
     std::exit(1);
   }
 }
diff --git a/crypto/func/func.h b/crypto/func/func.h
index 751e50a9..2f9877a0 100644
--- a/crypto/func/func.h
+++ b/crypto/func/func.h
@@ -35,10 +35,11 @@ namespace funC {
 
 extern int verbosity;
 extern bool op_rewrite_comments;
+extern std::string generated_from;
 
 constexpr int optimize_depth = 20;
 
-const std::string func_version{"0.1.0"};
+const std::string func_version{"0.2.0"};
 
 enum Keyword {
   _Eof = -1,
@@ -110,7 +111,8 @@ enum Keyword {
   _Infixl,
   _Infixr,
   _Const,
-  _PragmaHashtag
+  _PragmaHashtag,
+  _IncludeHashtag
 };
 
 void define_keywords();
@@ -828,9 +830,11 @@ extern std::vector<SymDef*> glob_func, glob_vars;
 
 // defined in parse-func.cpp
 bool parse_source(std::istream* is, const src::FileDescr* fdescr);
-bool parse_source_file(const char* filename);
+bool parse_source_file(const char* filename, src::Lexem lex = {});
 bool parse_source_stdin();
 
+extern std::stack<src::SrcLocation> inclusion_locations;
+
 /*
  * 
  *   EXPRESSIONS
diff --git a/crypto/func/keywords.cpp b/crypto/func/keywords.cpp
index b7bba0c2..3f0fa230 100644
--- a/crypto/func/keywords.cpp
+++ b/crypto/func/keywords.cpp
@@ -127,7 +127,9 @@ void define_keywords() {
       .add_keyword("infixl", Kw::_Infixl)
       .add_keyword("infixr", Kw::_Infixr)
       .add_keyword("const", Kw::_Const);
-  sym::symbols.add_keyword("#pragma", Kw::_PragmaHashtag);
+
+  sym::symbols.add_keyword("#pragma", Kw::_PragmaHashtag)
+      .add_keyword("#include", Kw::_IncludeHashtag);
 }
 
 }  // namespace funC
diff --git a/crypto/func/parse-func.cpp b/crypto/func/parse-func.cpp
index 929f5b3c..c33a3cda 100644
--- a/crypto/func/parse-func.cpp
+++ b/crypto/func/parse-func.cpp
@@ -23,6 +23,7 @@
 #include "block/block.h"
 #include "block-parse.h"
 #include <fstream>
+#include <climits>
 
 namespace sym {
 
@@ -1607,12 +1608,35 @@ void parse_pragma(Lexer& lex) {
 
 std::vector<const src::FileDescr*> source_fdescr;
 
+std::vector<std::string> source_files;
+std::stack<src::SrcLocation> inclusion_locations;
+
+void parse_include(Lexer& lex, const src::FileDescr* fdescr) {
+  auto include = lex.cur();
+  lex.expect(_IncludeHashtag);
+  if (lex.tp() != _String) {
+    lex.expect(_String, "source file name");
+  }
+  std::string val = lex.cur().str;
+  std::string parent_dir = fdescr->filename;
+  if (parent_dir.rfind('/') != std::string::npos) {
+    val = parent_dir.substr(0, parent_dir.rfind('/') + 1) + val;
+  }
+  lex.next();
+  lex.expect(';');
+  if (!parse_source_file(val.c_str(), include)) {
+    include.error(std::string{"failed parsing included file `"} + val + "`");
+  }
+}
+
 bool parse_source(std::istream* is, src::FileDescr* fdescr) {
   src::SourceReader reader{is, fdescr};
   Lexer lex{reader, true, ";,()[] ~."};
   while (lex.tp() != _Eof) {
     if (lex.tp() == _PragmaHashtag) {
       parse_pragma(lex);
+    } else if (lex.tp() == _IncludeHashtag) {
+      parse_include(lex, fdescr);
     } else if (lex.tp() == _Global) {
       parse_global_var_decls(lex);
     } else if (lex.tp() == _Const) {
@@ -1624,17 +1648,48 @@ bool parse_source(std::istream* is, src::FileDescr* fdescr) {
   return true;
 }
 
-bool parse_source_file(const char* filename) {
+bool parse_source_file(const char* filename, src::Lexem lex) {
   if (!filename || !*filename) {
-    throw src::Fatal{"source file name is an empty string"};
+    auto msg = "source file name is an empty string";
+    if (lex.tp) {
+      lex.error(msg);
+    } else {
+      throw src::Fatal{msg};
+    }
   }
+  char realpath_buf[PATH_MAX] = {0, };
+  realpath(filename, realpath_buf);
+  std::string real_filename = std::string{realpath_buf};
+  if (std::count(source_files.begin(), source_files.end(), real_filename)) {
+    if (verbosity >= 2) {
+      if (lex.tp) {
+        lex.loc.show_warning(std::string{"skipping file "} + real_filename + " because it was already included");
+      } else {
+        std::cerr << "warning: skipping file " << real_filename << " because it was already included" << std::endl;
+      }
+    }
+    return true;
+  }
+  if (lex.tp) { // included
+    funC::generated_from += std::string{"incl:"};
+  }
+  funC::generated_from += std::string{"`"} + filename + "` ";
+  source_files.push_back(real_filename);
   src::FileDescr* cur_source = new src::FileDescr{filename};
   source_fdescr.push_back(cur_source);
   std::ifstream ifs{filename};
   if (ifs.fail()) {
-    throw src::Fatal{std::string{"cannot open source file `"} + filename + "`"};
+    auto msg = std::string{"cannot open source file `"} + filename + "`";
+    if (lex.tp) {
+      lex.error(msg);
+    } else {
+      throw src::Fatal{msg};
+    }
   }
-  return parse_source(&ifs, cur_source);
+  inclusion_locations.push(lex.loc);
+  bool res = parse_source(&ifs, cur_source);
+  inclusion_locations.pop();
+  return res;
 }
 
 bool parse_source_stdin() {
diff --git a/crypto/func/test/i1.fc b/crypto/func/test/i1.fc
new file mode 100644
index 00000000..2b95e2dd
--- /dev/null
+++ b/crypto/func/test/i1.fc
@@ -0,0 +1,14 @@
+global int i;
+
+#include "i1sub1.fc";
+
+() sub0() impure { i = 0; }
+
+#include "i1sub2.fc";
+
+() main() impure {
+  sub0();
+  sub1();
+  sub2();
+  i = 9;
+}
diff --git a/crypto/func/test/i1sub1.fc b/crypto/func/test/i1sub1.fc
new file mode 100644
index 00000000..c905bf22
--- /dev/null
+++ b/crypto/func/test/i1sub1.fc
@@ -0,0 +1,6 @@
+;; DO NOT COMPILE DIRECTLY!
+;; Compile i1.fc
+
+() sub1() impure {
+  i = 1;
+}
diff --git a/crypto/func/test/i1sub2.fc b/crypto/func/test/i1sub2.fc
new file mode 100644
index 00000000..b7f200db
--- /dev/null
+++ b/crypto/func/test/i1sub2.fc
@@ -0,0 +1,8 @@
+;; DO NOT COMPILE DIRECTLY!
+;; Compile i1.fc
+
+() sub2() impure {
+  sub1();
+  sub0();
+  i = 2;
+}