diff --git a/src/streams.jl b/src/streams.jl
index 78b9c44..8f8f2f7 100644
--- a/src/streams.jl
+++ b/src/streams.jl
@@ -569,7 +569,7 @@ name of the component.
 """
 function readstreamhistory!(fs, streamname, filename; ismoleflow=false)
 
-    data, header = readdlm(filename, ',', '\n', header=true)
+    data, header = readdlm(lowercase(filename), ',', '\n', header=true)
     comps = string.(header[2:end]) # readdlm returns an array of AbstractStrings for some reason
     flows = data[:, 2:end]
     timestamps = DateTime.(data[:, 1], "yyyy/mm/dd HH:MM")
@@ -590,9 +590,9 @@ Writes in a stream history file (CSV file).
 """
 function writestreamhistory(stream, filename, moleflow=false)
     if moleflow
-        writetimearray(stream.moleflows, filename, format="yyyy/mm/dd HH:MM", delim=',')
+        writetimearray(stream.moleflows, lowercase(filename), format="yyyy/mm/dd HH:MM", delim=',')
     else
-        writetimearray(stream.massflows, filename, format="yyyy/mm/dd HH:MM", delim=',')
+        writetimearray(stream.massflows, lowercase(filename), format="yyyy/mm/dd HH:MM", delim=',')
     end
 
     return nothing
diff --git a/test/components/Argon.comp b/test/components/Argon.comp
deleted file mode 100644
index f6e1f13..0000000
--- a/test/components/Argon.comp
+++ /dev/null
@@ -1,5 +0,0 @@
-Argon
-1
-Ar
-1
-39.948
\ No newline at end of file
diff --git a/test/components/Nitrogen.comp b/test/components/Nitrogen.comp
deleted file mode 100644
index 36596ee..0000000
--- a/test/components/Nitrogen.comp
+++ /dev/null
@@ -1,5 +0,0 @@
-Nitrogen
-1
-N
-2
-28.0134
\ No newline at end of file
diff --git a/test/runtests.jl b/test/runtests.jl
index c9c0ee1..e5caed8 100644
--- a/test/runtests.jl
+++ b/test/runtests.jl
@@ -3,6 +3,27 @@ using Test
 
 @testset "Streams" begin
     fs = Flowsheet()
+
+    @comp begin
+        "C" --> 2
+        "H" --> 4
+    end "Ethylene" fs
+    dummy = writecomponent(joinpath(@__DIR__, "components", "Ethylene.comp"), fs.comps["Ethylene"])
+    @test dummy == 25
+
+    @comp begin
+        "C" --> 2
+        "H" --> 6
+    end "Ethane" fs
+    dummy = writecomponent(joinpath(@__DIR__, "components", "Ethane.comp"), fs.comps["Ethane"])
+    @test dummy == 24
+
+    @comp begin
+        "H" --> 2
+    end "Hydrogen" fs
+    dummy = writecomponent(joinpath(@__DIR__, "components", "Hydrogen.comp"), fs.comps["Hydrogen"])
+    @test dummy == 21
+
     count = readcomponentlist!(fs, joinpath(@__DIR__, "components"), ["Ethylene", "Ethane", "Hydrogen"])
     @test count == 3
     @test fs.comps["Ethylene"].Mr ≈ 28.053