diff --git a/Dockerfile b/Dockerfile
index eba9a1f..babb597 100644
--- a/Dockerfile
+++ b/Dockerfile
@@ -6,6 +6,7 @@ RUN install_vim -tag v8.0.0027 -build \
 ENV PACKAGES="\
     bash \
     git \
+    make \
     python \
     py-pip \
 "
diff --git a/ale_linters/c/clang.vim b/ale_linters/c/clang.vim
index 74279b7..366cf2d 100644
--- a/ale_linters/c/clang.vim
+++ b/ale_linters/c/clang.vim
@@ -12,7 +12,7 @@ endfunction
 function! ale_linters#c#clang#GetCommand(buffer) abort
 let l:cflags = []
     if g:ale_c_clang_parse_makefile
-        let l:cflags = join(ale#c#ParseMakefile(a:buffer), ' ') . ' '
+        let l:cflags = join(ale#c#ParseMakefile(a:buffer), ' ')
     endif
     if empty(l:cflags)
         let l:cflags = ale#c#IncludeOptions(ale#c#FindLocalHeaderPaths(a:buffer))