diff --git a/Makefile b/Makefile
index bb4952b..1700f61 100644
--- a/Makefile
+++ b/Makefile
@@ -49,7 +49,7 @@ ifdef BOOST_ROOT
 	LDFLAGS += -L$(BOOST_ROOT)/lib
 else
 	ifdef BOOST_INCLUDE
-		CPPFLAGS += -I$(BOOST_INCLUDE
+		CPPFLAGS += -I$(BOOST_INCLUDE)
 	endif
 
 	ifdef BOOST_LIB
diff --git a/README.md b/README.md
new file mode 100644
index 0000000..a7a95b6
--- /dev/null
+++ b/README.md
@@ -0,0 +1,7 @@
+# cta
+C++ implementation of Buenrostro adapter trimming
+
+Installation:
+`make CPPFLAGS="-I/path/to/boost/include"`
+
+Where `/path/to/boost/include` is the folder containing header files for [Boost](https://www.boost.org/) (can be installed with `conda install -c conda-forge boost`, placing it in `~/conda/env/your_env/include`)
diff --git a/src/cta.cpp b/src/cta.cpp
index cefd9da..933103c 100644
--- a/src/cta.cpp
+++ b/src/cta.cpp
@@ -84,8 +84,9 @@ bool is_gzipped_filename(const std::string& filename) {
 }
 
 std::regex fastq_filename_re("\\.(fq|fastq)?(\\.gz)?$");
-std::string make_trimmed_filename(const std::string& filename) {
-    return std::regex_replace(filename, fastq_filename_re, ".trimmed.fq.gz");
+std::string make_trimmed_filename(const std::string filename) {
+    std::string substitution = ".trimmed.fq.gz";
+    return std::regex_replace(filename, fastq_filename_re, substitution);
 }
 
 std::map<char, char> nucleotide_complements = {