diff --git a/src/source_clang.cpp b/src/source_clang.cpp
index 1d72a35..ec643d9 100644
--- a/src/source_clang.cpp
+++ b/src/source_clang.cpp
@@ -390,12 +390,13 @@ void Source::ClangViewParse::update_diagnostics() {
             diagnostic.fix_its.emplace_back(clangmm::Diagnostic::FixIt{"#include <" + *cpp_header + ">\n", file_path.string(), get_new_include_offsets()});
         }
       };
-      if(diagnostic.fix_its.empty() && diagnostic.severity >= clangmm::Diagnostic::Severity::Error) {
+      if(diagnostic.fix_its.empty() && diagnostic.severity >= clangmm::Diagnostic::Severity::Warning) {
         for(size_t c = 0; c < clang_tokens->size(); c++) {
           auto &token = (*clang_tokens)[c];
           auto &token_offsets = clang_tokens_offsets[c];
           if(static_cast<unsigned int>(line) == token_offsets.first.line - 1 && static_cast<unsigned int>(index) >= token_offsets.first.index - 1 && static_cast<unsigned int>(index) <= token_offsets.second.index - 1) {
-            if(starts_with(diagnostic.spelling, "implicit instantiation of undefined template")) {
+            if(diagnostic.severity >= clangmm::Diagnostic::Severity::Error &&
+               starts_with(diagnostic.spelling, "implicit instantiation of undefined template")) {
               size_t start = 44 + 2;
               if(start < diagnostic.spelling.size()) {
                 auto end = diagnostic.spelling.find('<', start);
@@ -417,30 +418,34 @@ void Source::ClangViewParse::update_diagnostics() {
                 }
               }
             }
-            if(is_token_char(*start) && token.get_kind() == clangmm::Token::Kind::Identifier &&
-               (starts_with(diagnostic.spelling, "unknown type name") ||
-                starts_with(diagnostic.spelling, "no type named") ||
-                starts_with(diagnostic.spelling, "no member named") ||
-                starts_with(diagnostic.spelling, "no template named") ||
-                starts_with(diagnostic.spelling, "use of undeclared identifier") ||
-                starts_with(diagnostic.spelling, "implicit instantiation of undefined template") ||
-                starts_with(diagnostic.spelling, "no viable constructor or deduction guide for deduction of template arguments of"))) {
-              auto token_string = get_token(start);
-              bool has_std = false;
-              if(is_cpp) {
-                if(token_string == "std" && c + 2 < clang_tokens->size() && (*clang_tokens)[c + 2].get_kind() == clangmm::Token::Kind::Identifier) {
-                  token_string = (*clang_tokens)[c + 2].get_spelling();
-                  has_std = true;
+            if(is_token_char(*start) && token.get_kind() == clangmm::Token::Kind::Identifier) {
+              if(diagnostic.severity >= clangmm::Diagnostic::Severity::Error &&
+                 (starts_with(diagnostic.spelling, "unknown type name") ||
+                  starts_with(diagnostic.spelling, "no type named") ||
+                  starts_with(diagnostic.spelling, "no member named") ||
+                  starts_with(diagnostic.spelling, "no template named") ||
+                  starts_with(diagnostic.spelling, "use of undeclared identifier") ||
+                  starts_with(diagnostic.spelling, "implicit instantiation of undefined template") ||
+                  starts_with(diagnostic.spelling, "no viable constructor or deduction guide for deduction of template arguments of"))) {
+                auto token_string = get_token(start);
+                bool has_std = false;
+                if(is_cpp) {
+                  if(token_string == "std" && c + 2 < clang_tokens->size() && (*clang_tokens)[c + 2].get_kind() == clangmm::Token::Kind::Identifier) {
+                    token_string = (*clang_tokens)[c + 2].get_spelling();
+                    has_std = true;
+                  }
+                  else if(c >= 2 &&
+                          (*clang_tokens)[c - 1].get_kind() == clangmm::Token::Punctuation &&
+                          (*clang_tokens)[c - 2].get_kind() == clangmm::Token::Identifier &&
+                          (*clang_tokens)[c - 1].get_spelling() == "::" &&
+                          (*clang_tokens)[c - 2].get_spelling() == "std")
+                    has_std = true;
                 }
-                else if(c >= 2 &&
-                        (*clang_tokens)[c - 1].get_kind() == clangmm::Token::Punctuation &&
-                        (*clang_tokens)[c - 2].get_kind() == clangmm::Token::Identifier &&
-                        (*clang_tokens)[c - 1].get_spelling() == "::" &&
-                        (*clang_tokens)[c - 2].get_spelling() == "std")
-                  has_std = true;
+                add_include_fixit(has_std, is_cpp && has_using_namespace_std(c), token_string);
               }
-
-              add_include_fixit(has_std, is_cpp && has_using_namespace_std(c), token_string);
+              else if(diagnostic.severity >= clangmm::Diagnostic::Severity::Warning && is_c &&
+                      starts_with(diagnostic.spelling, "implicitly declaring library function"))
+                add_include_fixit(false, false, get_token(start));
             }
             break;
           }