diff --git a/.travis.yml b/.travis.yml
index 85ebefe..44abfd5 100644
--- a/.travis.yml
+++ b/.travis.yml
@@ -57,6 +57,6 @@ install:
 
 script:
   - mkdir build/ && cd build/
-  - $CMAKE -DCMAKE_CXX_FLAGS="-pedantic -Wall -Wextra -Wconversion -Wsign-conversion -Wno-parentheses" -DLLVM_DOWNLOAD_OS_NAME=$LLVM_DOWNLOAD_OS_NAME -DLLVM_PREFERRED_VERSION=$LLVM_VERSION ../
+  - $CMAKE -DCMAKE_CXX_FLAGS="-Werror -pedantic -Wall -Wextra -Wconversion -Wsign-conversion -Wno-parentheses" -DLLVM_DOWNLOAD_OS_NAME=$LLVM_DOWNLOAD_OS_NAME -DLLVM_PREFERRED_VERSION=$LLVM_VERSION ../
   - $CMAKE --build .
   - ./test/cppast_test
diff --git a/external/tiny-process-library b/external/tiny-process-library
index 7539bc3..50f6919 160000
--- a/external/tiny-process-library
+++ b/external/tiny-process-library
@@ -1 +1 @@
-Subproject commit 7539bc3f0c23104accc09f5c024d6b3609f0debe
+Subproject commit 50f69197c2af03dc93cd0985a39d6809c80a27b5
diff --git a/src/libclang/tokenizer.cpp b/src/libclang/tokenizer.cpp
index c127769..d972272 100644
--- a/src/libclang/tokenizer.cpp
+++ b/src/libclang/tokenizer.cpp
@@ -30,7 +30,11 @@ namespace
     {
         unsigned offset;
         clang_getSpellingLocation(loc, nullptr, nullptr, nullptr, &offset);
-        return clang_getLocationForOffset(tu, file, offset + inc);
+        if (inc >= 0)
+            offset += unsigned(inc);
+        else
+            offset -= unsigned(-inc);
+        return clang_getLocationForOffset(tu, file, offset);
     }
 
     class simple_tokenizer
@@ -312,7 +316,7 @@ detail::token_iterator detail::find_closing_bracket(detail::token_stream stream)
             --bracket_count;
         else if (paren_count == 0 && template_bracket && cur == ">>")
             // maximal munch
-            bracket_count -= 2u;
+            bracket_count -= 2;
         else if (cur == "(" || cur == "{" || cur == "[")
             ++paren_count;
         else if (cur == ")" || cur == "}" || cur == "]")
diff --git a/tool/main.cpp b/tool/main.cpp
index afcbab3..c33d8a7 100644
--- a/tool/main.cpp
+++ b/tool/main.cpp
@@ -288,7 +288,7 @@ int main(int argc, char* argv[])
             logger.set_verbose(true);
 
         auto file = parse_file(config, logger, options["file"].as<std::string>(),
-                               options.count("fatal_errors") == 1u);
+                               options.count("fatal_errors") == 1);
         if (!file)
             return 2;
         print_ast(std::cout, *file);